Delta Air Lines Reliability

Reliability

July 2023 – July 2026

Airline Reliability Score

71/ 100Good

Better than 90% of US reporting carriers (15 compared)

Calculated from 3,146,502 flights. How this is calculated

On-time arrivals

82.1%

2,545,736 of 3,102,125

Cancellation rate

1.16%

36,539 cancelled

Median arrival delay

-8 min

Average 3.9 min

Severe delays

6.3%

60+ minutes late

Delay when late

72 min

Average, when 15+ min late

Departure punctuality

82.1%

Left the gate on time

Against the 15 carriers FlyerIntel covers — all measured over the same period, from the same source — Delta Air Lines ranks 4th of 15 for on-time arrivals, 4th for cancellations and 5th for arrivals more than an hour late. The full table is at the foot of this page.

Over the most recent 12 months (2025-08 to 2026-07) Delta Air Lines arrived on time 81.5% of the time, against 81.5% in the 12 months before (2024-08 to 2025-07) — broadly unchanged.

Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026

Why Delta Air Lines cancels flights

Every cancellation carries a reason code the operating carrier filed with US DOT. July 2023 – July 2026.

Delta Air Lines cancelled 36,539 of 3,146,502 scheduled flights — about 1 in every 86. The reason it filed most often was the airline, 55.9% of the cancellations it coded — about 1 in every 154 scheduled flights.

Share of cancellations

Airline55.9%

Weather39.6%

Air traffic4.4%

Security0.2%

Of 36,539 cancelled departures carrying a reason code.

What each reason means

The airline1 in 154

Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.

20,408 cancellations, 55.9% of the total.

Extreme weather1 in 217

Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.

14,477 cancellations, 39.6% of the total.

The air traffic system1 in 1,968

Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.

1,599 cancellations, 4.4% of the total.

Security1 in 57,209

A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.

55 cancellations, 0.2% of the total.

What these shares do not measure

A reason code is the operating carrier’s own filing. US DOT collects the reason the airline gave; it does not adjudicate it, and carriers differ in how they fill the form in. The split above describes what kind of disruption Delta Air Lines records, not who was at fault when it happened, and it cannot be set against another airline’s split to decide which of the two is better run.

That is measurable rather than a disclaimer. Across the 15 carriers FlyerIntel publishes, the correlation between how much of its own canceling a carrier attributes to itself and how often it actually cancels is -0.46 — negative, which is the wrong sign for a ranking of fault and about the right sign for a difference in filing convention. Hawaiian Airlines attributed 82.8% of its cancellations to itself and cancelled 1.00% of its flights; SkyWest Airlines attributed 2.7% and cancelled 1.33%. The airline taking the most blame is the one that cancels least.

The figure on this page that does compare cleanly between airlines is the cancellation rate in Reliability, because it counts cancellations instead of reading the reason filed for them. The First Flight of the Day sets out the same finding from the airport-carrier records, and declines on the strength of it to compare any two carriers’ codes.

Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.

By airport

Delta Air Lines cancellation causes by airport
Airport	Cancelled	Rate	Airline	Weather	Air traffic	Security
ATL Atlanta	8,628	1.20%	56%	41%	2%	<1%
LGA New York	2,116	2.45%	35%	52%	13%	0%
DTW Detroit	1,809	0.99%	59%	35%	6%	<1%
MSP Minneapolis	1,620	0.78%	60%	36%	5%	<1%
JFK New York	1,496	1.60%	39%	54%	7%	<1%
BOS Boston	1,036	1.29%	51%	42%	8%	<1%
SLC Salt Lake City	971	0.58%	74%	24%	2%	0%
MCO Orlando	904	1.37%	45%	49%	6%	0%
LAX Los Angeles	827	0.73%	74%	24%	2%	0%
SEA Seattle	689	0.69%	71%	27%	2%	0%
TPA Tampa	684	1.67%	36%	61%	4%	0%
ORD Chicago	588	1.75%	48%	35%	17%	0%
DFW Dallas–Fort Worth	574	1.56%	52%	44%	5%	0%
FLL Fort Lauderdale	550	1.42%	52%	42%	6%	0%
DCA Washington	505	1.79%	45%	47%	9%	0%
MIA Miami	501	1.43%	46%	46%	8%	0%

Shares are of Delta Air Lines’s own coded cancellations at each airport and run across the row, so they total 100%. “Rate” is cancellations as a share of its scheduled departures there. Reading down a column compares one airline with itself in different weather and different airspace, which is the comparison these codes support — a carrier files the same way wherever it flies, so its filing habits largely cancel out of the differences between these rows in a way they never cancel out of a comparison between two airlines. Airports where Delta Air Lines recorded fewer coded cancellations than the published minimum are not listed.

Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026 · These are the reason codes Delta Air Lines itself filed with US DOT — the reason the airline gave, not an independent finding of fault, and airlines differ in how they apply them. FlyerIntel publishes the split only for carriers with at least 500 coded cancellations in the period; 36,539 were recorded. Whatever the reason code, a cancelled flight may qualify for an automatic refund under DOT’s rule — the refund checker covers eligibility.

Reliability over time

24

25

26

Each column is one month of Delta Air Lines operations. The strongest single month of the period was November 2023 at 91.4% on time; the weakest was July 2024 at 70.1%. Individual months move for reasons that do not repeat — a hurricane season, a technology outage, a winter storm — which is why the section below combines the same data by calendar month instead.

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026

Best and worst months to fly

Every Delta Air Lines January stacked on every other January, and so on through the year.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Delta Air Lines — best and worst months to fly
Month	Flights	On time	Cancelled
January	229,888	80.7%	2.50%
February	216,751	84.0%	0.84%
March	254,045	81.7%	1.42%
April	254,115	83.9%	0.50%
May	270,267	79.7%	0.56%
June	270,434	78.7%	1.02%
July	370,253	73.9%	2.97%
August	269,767	81.7%	1.08%
September	251,121	87.0%	0.33%
October	263,764	88.3%	0.45%
November	246,653	87.5%	0.60%
December	249,444	81.7%	0.97%

Combining 3 to 4 years of operations by calendar month, Delta Air Lines is at its best in October, when 88.3% of arrivals were on time, and at its worst in July at 73.9% — a spread of 14.4 percentage points between two months of the same airline. Cancellations peak in the same month: July at 2.97% of flights, against 0.33% in September.

This is the shape of the calendar, not a forecast. It says that if you book Delta Air Lines in July you are booking into the part of the year when this airline has historically been least punctual, and that an October itinerary starts from a better position. It does not say anything about a particular date, and it cannot: the figure behind each month is 3 to 4 years of that same month combined, precisely so that one storm does not decide the answer.

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Rates are recalculated from the summed monthly counts, so a heavy month carries more weight than a light one.

Best time to fly Delta Air Lines

How Delta Air Lines departures have done at each hour of each weekday, across its whole network.

By day and hour

On-time arrival rate for each weekday and scheduled departure hour, in local time at the airport each flight leaves from, so the grid mixes time zones across the network.

Wednesday 5–6 AM was the most reliable slot for Delta Air Lines (93.1% on time, 11,571 flights) and Sunday 7–8 PM the least (67.7%, 26,220 flights).

Hour of departure matters more than day of the week: hourly averages sit a typical 5.6 points from the network-wide rate, weekday averages 2.1 points.

On-time arrival rate for Delta Air Lines by weekday and scheduled departure hour, local time. Each button reads out one slot.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
12 AM–1 AM
1 AM–2 AM
2 AM–3 AM
3 AM–4 AM
4 AM–5 AM
5 AM–6 AM
6 AM–7 AM
7 AM–8 AM
8 AM–9 AM
9 AM–10 AM
10 AM–11 AM
11 AM–12 PM
12 PM–1 PM
1 PM–2 PM
2 PM–3 PM
3 PM–4 PM
4 PM–5 PM
5 PM–6 PM
6 PM–7 PM
7 PM–8 PM
8 PM–9 PM
9 PM–10 PM
10 PM–11 PM
11 PM–12 AM

On-time rate, % · stronger color, fewer on time

68–71
72–75
76–79
80–83
84–87
88–91
92–95

Fewer than 120 flights, not scored
Most reliable slot
Least reliable slot

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · On time is arrival within 15 minutes of schedule. Cells round to whole percentages; the table shows one decimal.

Best and worst slots are named only among slots with 500+ flights, and only when the gap is larger than sampling error.

View as tableHide table

On-time arrival rate (%) with flights beneath, by scheduled departure hour and weekday for Delta Air Lines. A dash means fewer than 120 flights, which are not scored.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
12 AM–1 AM	83.1% on time1,129 flights	87.9% on time1,039 flights	90.7% on time730 flights	89.6% on time846 flights	86.0% on time1,106 flights	86.9% on time1,142 flights	91.1% on time704 flights
1 AM–2 AM	75.3% on time297 flights	78.6% on time299 flights	81.8% on time276 flights	82.2% on time284 flights	78.9% on time297 flights	79.7% on time299 flights	81.7% on time267 flights
2 AM–3 AM	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score
3 AM–4 AM	7 flights, too few to score	7 flights, too few to score	7 flights, too few to score	7 flights, too few to score	8 flights, too few to score	8 flights, too few to score	10 flights, too few to score
4 AM–5 AM	1 flight, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score	0 flights, too few to score
5 AM–6 AM	91.3% on time11,763 flights	92.7% on time11,596 flights	93.1% on time11,571 flights	92.9% on time11,704 flights	92.3% on time11,721 flights	91.3% on time10,977 flights	91.4% on time11,522 flights
6 AM–7 AM	90.5% on time32,865 flights	91.9% on time32,621 flights	92.4% on time32,413 flights	92.0% on time32,770 flights	90.8% on time32,785 flights	90.8% on time30,540 flights	90.1% on time31,245 flights
7 AM–8 AM	87.6% on time38,990 flights	89.7% on time38,223 flights	89.8% on time38,158 flights	89.3% on time38,843 flights	87.9% on time38,858 flights	88.3% on time34,778 flights	87.5% on time37,990 flights
8 AM–9 AM	86.5% on time28,790 flights	88.1% on time28,612 flights	89.2% on time28,616 flights	87.7% on time28,848 flights	87.0% on time28,909 flights	86.8% on time27,900 flights	86.0% on time28,954 flights
9 AM–10 AM	85.7% on time23,311 flights	87.8% on time22,792 flights	88.7% on time22,825 flights	87.3% on time23,151 flights	85.8% on time23,140 flights	85.5% on time21,468 flights	84.9% on time23,236 flights
10 AM–11 AM	84.8% on time25,936 flights	87.3% on time25,259 flights	88.4% on time25,379 flights	86.5% on time25,830 flights	84.8% on time25,911 flights	84.8% on time22,947 flights	83.6% on time25,530 flights
11 AM–12 PM	82.5% on time32,961 flights	86.2% on time32,404 flights	86.4% on time32,530 flights	84.1% on time32,865 flights	82.6% on time32,929 flights	83.2% on time31,568 flights	81.3% on time32,842 flights
12 PM–1 PM	82.2% on time27,932 flights	85.5% on time27,415 flights	86.3% on time27,515 flights	83.8% on time27,882 flights	82.1% on time27,888 flights	82.6% on time25,272 flights	79.8% on time27,839 flights
1 PM–2 PM	80.8% on time25,418 flights	84.5% on time24,598 flights	85.0% on time24,726 flights	82.6% on time25,294 flights	80.8% on time25,387 flights	81.6% on time22,990 flights	78.2% on time25,088 flights
2 PM–3 PM	79.3% on time23,098 flights	82.9% on time22,350 flights	83.2% on time22,401 flights	80.2% on time22,805 flights	78.7% on time22,982 flights	80.0% on time20,926 flights	76.1% on time22,934 flights
3 PM–4 PM	76.9% on time31,451 flights	80.4% on time30,348 flights	80.6% on time30,470 flights	77.0% on time31,244 flights	75.8% on time31,283 flights	78.8% on time27,745 flights	73.4% on time31,089 flights
4 PM–5 PM	75.8% on time21,880 flights	80.2% on time20,231 flights	80.4% on time20,233 flights	76.1% on time21,684 flights	74.4% on time21,843 flights	77.4% on time19,001 flights	72.0% on time21,648 flights
5 PM–6 PM	76.6% on time28,058 flights	80.2% on time26,965 flights	80.6% on time27,100 flights	75.6% on time27,769 flights	74.5% on time27,933 flights	78.8% on time25,474 flights	72.5% on time27,711 flights
6 PM–7 PM	75.3% on time27,465 flights	79.2% on time26,002 flights	78.6% on time26,269 flights	74.0% on time26,947 flights	73.5% on time27,260 flights	76.7% on time21,433 flights	70.9% on time26,859 flights
7 PM–8 PM	72.6% on time26,832 flights	77.8% on time21,925 flights	77.4% on time22,237 flights	71.9% on time26,410 flights	72.1% on time26,722 flights	73.8% on time15,741 flights	67.7% on time26,220 flights
8 PM–9 PM	73.2% on time17,685 flights	77.8% on time14,218 flights	77.8% on time14,501 flights	71.6% on time17,463 flights	70.9% on time17,690 flights	76.3% on time11,547 flights	68.2% on time17,595 flights
9 PM–10 PM	76.0% on time17,512 flights	82.2% on time14,502 flights	81.0% on time14,843 flights	75.9% on time17,408 flights	74.4% on time17,536 flights	81.0% on time14,885 flights	72.2% on time17,426 flights
10 PM–11 PM	79.0% on time16,168 flights	84.1% on time14,885 flights	84.0% on time15,039 flights	78.1% on time15,969 flights	76.5% on time16,206 flights	82.1% on time12,518 flights	74.1% on time16,102 flights
11 PM–12 AM	78.8% on time7,356 flights	85.7% on time5,817 flights	85.0% on time6,022 flights	77.9% on time7,381 flights	76.8% on time7,483 flights	84.2% on time4,850 flights	74.8% on time7,527 flights

Why Delta Air Lines runs late

Share of total reported delay minutes by cause, as classified by the operating carrier.

The airline45.6%

crew, maintenance, boarding and fueling, all within the carrier’s control

Late-arriving aircraft29.7%

the inbound aircraft was late, so this flight started late

Air traffic control20.0%

airspace and airport capacity, including weather-driven flow control

Weather4.7%

weather severe enough to stop this flight specifically

Security0.1%

screening or terminal security incidents

Share of the delay minutes US DOT attributed to each cause for Delta Air Lines. Only delays of 15 minutes or more are attributed.

The largest single category for Delta Air Lines is the airline itself, at 45.6% of attributed minutes. That is the one category squarely inside the carrier’s own control — crew, maintenance, boarding, fueling — and across the 15 carriers covered here it accounts for 33.9% of attributed minutes. That is 11.7 percentage points more of its delay minutes falling inside the airline than is typical for this group.

These shares describe how delay minutes were divided, not how often delays happened. A carrier with an unusually large air-traffic-control share is not necessarily worse run; it may simply fly more of its schedule through congested airspace. The one category that is squarely the airline’s own is the carrier category, which is why it is the one compared above.

Source: US DOT BTS delay cause categories · July 2023 – July 2026 · Cause minutes are only reported for arrivals delayed 15 minutes or more.

How Delta Air Lines handles bad weather

Departures by the weather at the origin in the hour they were scheduled to leave, July 2023 – July 2026.

10% of Delta Air Lines’ weather-matched departures left in an hour of bad weather at the origin. 2.7% of them were cancelled, 2.9 times the 1.0% cancelled in normal hours, and 69.5% of those that flew arrived on time, against 82.8%. Those hours held 23% of the airline’s cancelled departures.

In bad weather Delta Air Lines cancelled fewer flights than other carriers: 2.8% of its departures in those hours were cancelled, against 4.0% for the other carriers at the same airports in the same months. It was below them in normal hours too (1.0% against 1.3%), so part of the difference is there in clear conditions as well. Its flights that operated arrived on time 69.3% of the time, 3.5 points above the others’ 65.8%.

Bad-weather hours against normal hours

Scheduled departures, July 2023 – July 2026

Delta Air Lines cancellation and on-time rates in bad-weather and normal hours at the origin, with the other carriers at the same airports and months
Weather at the origin	Departures	Cancelled	Arrived on time
Normal hours	2,244,613	1.0%	82.8%
Other carriers	2,244,613compared	1.3%	79.1%
Bad-weather hours	267,22510% of all matched	2.7%2.9 times normal	69.5%13.3 points below normal
Other carriers	262,282compared	4.0%	65.8%

Bad weather means IFR or LIFR conditions, or a storm, snow, ice, fog, heavy rain or high wind, at the origin; normal means VFR with none of those. Marginal hours are in neither row, and were 9% of Delta Air Lines’ matched departures. Cancelled is the share of scheduled departures. The other carriers’ rows apply their rate in each airport and month to the departures Delta Air Lines had there.

The most exposed airports were LGA (6.5% of 10,841), EWR (5.4% of 2,694), DCA (5.3% of 2,726); the least, SLC (0.5% of 9,247), SNA (0.5% of 935), PDX (0.7% of 1,278). It did best against the others at DFW, Dallas–Fort Worth: 4.2% cancelled against 10.4%.

Most exposed airports

Most exposed airports: Delta Air Lines departures in bad weather by airport
Airport	Departures	Cancelled	Other carriers	Normal hours
LGA New York	10,841	6.5%	9.9%	1.6%
EWR Newark	2,694	5.4%	7.0%	1.5%
DCA Washington	2,726	5.3%	10.0%	1.4%

Least exposed airports

Least exposed airports: Delta Air Lines departures in bad weather by airport
Airport	Departures	Cancelled	Other carriers	Normal hours
SLC Salt Lake City	9,247	0.5%	0.7%	0.6%
SNA Santa Ana	935	0.5%	2.3%	0.8%
PDX Portland	1,278	0.7%	1.9%	0.7%

Airports are listed with at least 500 of Delta Air Lines’ bad-weather departures and 500 weather-matched departures in all. Other carriers is their cancellation rate in the same airport and months, applied to Delta Air Lines’ departures there, and is left blank where Delta Air Lines was nearly the only carrier flying in the bad-weather hours of most months and there is no one to compare with.

This is the weather reported at the origin in the hour a flight was scheduled to leave, July 2023 – July 2026. It leaves out the weather at the destination and on the way, and an hour takes the worst conditions any report in it gave. Weather was matched to 88.1% of Delta Air Lines’ scheduled departures: the rest left from airports with no archived weather, in hours with no report, or at a scheduled time the flight records cannot place exactly. The comparison covers 1,764 airport-months in which Delta Air Lines flew in bad weather; the other carriers are held to the same airport and calendar month, not the same hour of the day or the same aircraft, so a carrier that schedules more of those departures at the busiest or the quietest times is not fully adjusted for. 4,943 of its bad-weather departures were in an airport and month where the other carriers had fewer than 120 of their own, and are not in that comparison.

Source: FlyerIntel analysis of US DOT BTS flight records and Iowa Environmental Mesonet weather reports · July 2023 – July 2026 · Where the weather comes from, and its limits. All covered airports side by side: What Weather Costs Each Airport.

Turning aircraft around at Delta Air Lines

Time on the ground between one flight and the next of the same aircraft, and what a late arrival does to the next departure, July 2023 – July 2026.

The median Delta Air Lines turn is scheduled for 69 minutes on the ground and takes 76 minutes, against 56 minutes and 63 minutes across all airlines. Delta Air Lines gives its aircraft longer on the ground than the network does. 15.5% of its turns began with an aircraft that landed 15 or more minutes late, against 18.9% for the network.

When the aircraft landed 15 or more minutes late (356,951 turns, 57 minutes late on average), 73% of the turns were finished in no more than the scheduled ground time, against 68% across all airlines. 68% of those flights left 15 or more minutes late, against 72%. After an aircraft that landed on time, 9% did (network 11%).

Given the turn lengths it schedules, the network’s rates would give 77% finished in the schedule and 64% leaving late. By that measure Delta Air Lines finished fewer late turns in the schedule and passed lateness on to the next departure more often than the network would have. 53% of its late-inbound turns had a scheduled turn of 60 to 89 minutes, against 29% of the network’s.

Turns, Delta Air Lines against the network

2,308,624 turns, July 2023 – July 2026

Delta Air Lines aircraft turns against all airlines: scheduled and actual time on the ground and what a late inbound aircraft does
Measure	Delta Air Lines	All airlines	All airlines, same turn lengths
Median scheduled turn	69 min	56 min	—
Median actual turn	76 min	63 min	—
Turns that began with an aircraft 15+ minutes late	15%	19%	—
Late turns finished within the schedule	73%	68%	77%
Late inbound that left 15+ minutes late	68%	72%	64%
On-time inbound that left 15+ minutes late	9%	11%	—

Late means 15 or more minutes. A turn finishes within the schedule when the aircraft spent no more time on the ground than the schedule gave it. The last column applies the network’s rate in each scheduled-turn band (under 30 minutes up to 3 to 6 hours) to the number of Delta Air Lines turns in that band, so it shows what the same turn lengths would give across all airlines.

A turn pairs an aircraft’s landing with its next departure by tail number; the aircraft is never named. These 2,308,624 turns are 73% of Delta Air Lines’ flights in the period; the rest are an aircraft’s first flight after a long stay, flights without a usable inbound, and cancelled flights. Ground time is measured from the gate: the scheduled turn plus the departing flight’s delay minus the inbound’s arrival delay. Overnight stays (6 hours or more on the ground), cancelled flights and flights whose inbound diverted are not turns here. Turns scheduled under 30 minutes are a small share and are kept, but they are rarely a plan for that aircraft (more often a swap or recovery, with the flight waiting for an aircraft that was not the one scheduled), so most of them across the network leave late even after an on-time landing. A flight that an airline covered with a different aircraft is linked to the one that flew it, not the one first planned.

Source: FlyerIntel analysis of US DOT BTS flight records · July 2023 – July 2026 · All airlines side by side: How Fast an Aircraft Turns When It Has To.

What sets Delta Air Lines apart

Where Delta Air Lines differs most from the other covered airlines, July 2023 – July 2026.

Delta Air Lines flights scheduled to leave at 10 PM arrive on time 79.5% of the time, 9.4 points better than the 70.1% the other covered airlines manage at that hour.

June suits Delta Air Lines more than it suits the other airlines: 78.7% on time against 72.8%, 5.9 points ahead.

SJU is where Delta Air Lines stands out most against local competition: 86.7% of its departures arrive on time, 11.7 points above the 75.0% of the other airlines out of the same airport.

Delta Air Lines against the other airlines

July 2023 – July 2026

Where Delta Air Lines differs most from the other covered airlines, with the flights behind each figure
Measure	Delta Air Lines	Elsewhere	Gap	Flights behind it
Hour: 10 PM departures	79.5%	70.1%	+9.4 pts	105,237 here, 390,344 elsewhere
Month: June	78.7%	72.8%	+5.9 pts	266,706 here, 1,529,233 elsewhere
Airport: SJU	86.7%	75.0%	+11.7 pts	10,991 here, 96,572 elsewhere

“Elsewhere” is every other covered airline together, from the same aggregates as this page. Hours and months appear only where both sides have at least 120 completed flights; airports only where Delta Air Lines and everyone else there each have at least 500. Gaps must be at least 2 points and 2 standard errors, and only the largest in each direction is shown. Airlines fly different airports, so the hour and month rows partly compare different traffic; the airport rows compare like with like. The taxi figure is weighted by departures, mixes airports, and has no error estimate, so it appears from 2 minutes.

Where this airline flies

Departure performance at the airports FlyerIntel covers.

Airports served

159

64 of them covered in detail here

Departures from its largest base

22.8%

ATL · Atlanta

Departures from its top three

35.3%

ATL, MSP, DTW

Delta Air Lines departed from 159 airports in this period, with no single one accounting for more than 22.8% of departures and the largest three together 35.3%. Performance is spread across the network rather than resting on one or two hubs, so a single weak airport moves this carrier’s overall figure less than it would at a hub-and-spoke airline.

Endeavor Air operates exclusively as Delta Air Lines’ own regional partner — not for any other airline, which is what makes its flights attributable to this brand at all. Across the 144 airports where Delta Air Lines itself has a real base, 8.2% of the combined departures were actually flown by it, not Delta Air Lines. The largest single example is LGA (New York), where 49,270 of 135,696 departures — 36.3% — were its. This excludes larger regional partners such as SkyWest and Republic, which also fly for other mainline brands and cannot be split between them from public flight data — see the network-wide comparison for the fuller picture.

Where this airline flies
Airport	Departures	On time	Cancelled	Median delay
ATL Atlanta	717,729	79.9%	1.20%	-5 min
MSP Minneapolis	208,199	81.2%	0.78%	-8 min
DTW Detroit	183,599	79.7%	0.99%	-7 min
SLC Salt Lake City	167,925	83.3%	0.58%	-8 min
LAX Los Angeles	113,873	82.3%	0.73%	-8 min
SEA Seattle	99,813	83.2%	0.69%	-8 min
JFK New York	93,774	79.3%	1.60%	-10 min
LGA New York	86,426	77.3%	2.45%	-9 min
BOS Boston	80,126	78.6%	1.29%	-8 min
MCO Orlando	66,032	77.9%	1.37%	-7 min
LAS Las Vegas	49,440	84.6%	0.77%	-10 min
SFO San Francisco	41,240	81.5%	0.82%	-9 min

Strongest airports

SJC (91.7%), ONT (91.5%), ABQ (91.0%)

Weakest airports

MIA (74.1%), EWR (77.1%), LGA (77.3%)

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Airports where this carrier flew fewer than 500 departures are not listed.

Route performance

Delta Air Lines’ own on-time rate on each route — this carrier's flights only, which can differ from the route's rate across every airline that flies it.

Most reliable

PDX→SEAPortland to Seattle92.3%PDX→LAXPortland to Los Angeles90.7%ANC→SEAAnchorage to Seattle90.3%PHX→SEAPhoenix to Seattle90.3%LAX→SLCLos Angeles to Salt Lake City89.7%PHX→SLCPhoenix to Salt Lake City89.4%HNL→LAXHonolulu to Los Angeles89.1%MCI→ATLKansas City to Atlanta88.7%

Least reliable

MIA→BOSMiami to Boston68.8%SLC→SFOSalt Lake City to San Francisco70.0%ATL→MCOAtlanta to Orlando70.7%BOS→ORDBoston to Chicago71.0%ATL→EWRAtlanta to Newark71.0%MIA→JFKMiami to New York71.0%ATL→MIAAtlanta to Miami71.0%ATL→DCAAtlanta to Washington71.4%

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Routes with fewer than 600 flights by this carrier are not ranked.

Where Delta Air Lines flies best and worst

The airports and routes where Delta Air Lines is on time most and least often, set beside the other airlines at the same place.

Delta Air Lines arrives on time 91.7% of the time at SJC, 8 points better than the 83.7% for the other airlines there.

Delta Air Lines arrives on time 91.5% of the time at ONT, 8.6 points better than the 82.9% for the other airlines there.

Delta Air Lines arrives on time 91.0% of the time at ABQ, 8.3 points better than the 82.7% for the other airlines there.

Delta Air Lines is on time 74.1% of the time at MIA, near the bottom of its own list, but the other airlines there are no better at 73.1%: the airport is hard for everyone.

Delta Air Lines is on time 77.1% of the time at EWR, near the bottom of its own list, but the other airlines there are no better at 77.7%: the airport is hard for everyone.

Delta Air Lines is on time 77.3% of the time at LGA, near the bottom of its own list, but the other airlines there are no better at 78.5%: the airport is hard for everyone.

Delta Air Lines arrives on time 92.3% of the time on PDX to SEA, 6.9 points better than the 85.4% for the other airlines on it.

Delta Air Lines arrives on time 90.7% of the time on PDX to LAX, 4.7 points better than the 86.0% for the other airlines on it.

Delta Air Lines arrives on time 90.3% of the time on ANC to SEA, 7.1 points better than the 83.2% for the other airlines on it.

Delta Air Lines is on time 68.8% of the time on MIA to BOS, near the bottom of its own list, but the other airlines on it are no better at 70.6%: the route is hard for everyone.

Delta Air Lines manages 70.0% on SLC to SFO, 2.8 points below the 72.8% for the other airlines on it.

Delta Air Lines is on time 70.7% of the time on ATL to MCO, near the bottom of its own list, but the other airlines on it are no better at 72.4%: the route is hard for everyone.

Airports, best and worst

Airports, best and worst: Delta Air Lines on-time rate beside the other airlines, with the flights behind each figure
Place	Delta Air Lines	Other airlines	Flights behind it
SJC	91.7%	83.7%	7,842 here, 138,083 others
ONT	91.5%	82.9%	5,693 here, 73,382 others
ABQ	91.0%	82.7%	4,239 here, 70,967 others
MIA	74.1%	73.1%	34,329 here, 299,938 others
EWR	77.1%	77.7%	19,798 here, 355,843 others
LGA	77.3%	78.5%	83,994 here, 356,051 others

Routes, best and worst

Routes, best and worst: Delta Air Lines on-time rate beside the other airlines, with the flights behind each figure
Place	Delta Air Lines	Other airlines	Flights behind it
PDX to SEA	92.3%	85.4%	1,215 here, 15,064 others
PDX to LAX	90.7%	86.0%	5,122 here, 8,308 others
ANC to SEA	90.3%	83.2%	5,048 here, 17,097 others
MIA to BOS	68.8%	70.6%	2,321 here, 8,933 others
SLC to SFO	70.0%	72.8%	5,160 here, 5,600 others
ATL to MCO	70.7%	72.4%	16,599 here, 9,691 others

July 2023 – July 2026. Airports need at least 2,000 completed flights by Delta Air Lines, routes 600. The other airlines are everyone else at the same airport or on the same route, compared only where they have at least 500 (airports) or 200 (routes) completed flights; a gap counts as ahead or behind only at 2 points and 2 standard errors. Route figures are for one direction. Airlines fly different times of day and aircraft, so a gap is a comparison, not a cause.

Most and least reliable flights

Individual Delta Air Lines flight numbers, ranked on the route each one flies today.

Most reliable

DL886TUS→ATL · 6:00 AM96.9%DL1535PHX→SLC · 6:00 AM96.8%DL1270PDX→SLC · 5:10 AM96.7%DL2369PDX→MSP · 6:00 AM96.3%DL2178SFO→MSP · 6:00 AM96.1%DL2674LAS→SLC · 6:00 AM96.0%DL1526SMF→SLC · 5:30 AM95.9%DL2844LAS→SEA · 6:00 AM95.4%

Least reliable

DL1454DTW→DCA · 2:59 PM52.9%DL2498ATL→EWR · 6:50 PM53.0%DL2879ATL→ORD · 5:25 PM54.7%DL2340ATL→EWR · 4:20 PM56.8%DL1497ATL→MCO · 5:15 PM57.6%DL2520LGA→MCO · 3:35 PM58.9%DL2527ATL→EWR · 8:59 PM59.0%DL2035ATL→MCO · 6:15 PM59.3%

1,146 Delta Air Lines flight numbers have operated their current route at least 600 times. The strongest of them, DL886 from Tucson to Atlanta, arrived on time 96.9% of the time. The weakest, DL1454 from Detroit to Washington, managed 52.9% — a gap of 44 percentage points inside one airline. The departures in the first column are scheduled to leave at a median of 6:00 AM; those in the second at 5:25 PM.

Choosing between two flights on the same airline and the same day is a decision most travelers make on price and timing alone, because nothing at the point of booking distinguishes them. These figures do. They are the record of the exact flight number, on the route it flies today, over the whole analysis period — not a carrier average applied to it.

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · A flight number is a slot in a schedule and gets reassigned to different city pairs over time, so each is measured only on the route it currently operates. Numbers with fewer than 600 operations on that route, or last flown more than a quarter ago, are not ranked. Schedules change — confirm a departure still operates before booking around it.

See all 1,146 Delta Air Lines flight numbers →

Compare airlines

Every carrier on FlyerIntel is measured the same way, over the same period, using the same source data. That is the whole point of the table: airline marketing reports punctuality on definitions of its own choosing, and this does not.

Compare airlines
Airline	Score	On time	Cancelled	60+ min late	Flights
Endeavor Air	70	85.1%	2.30%	6.0%	304,230
Hawaiian Airlines	80	83.7%	1.00%	2.9%	199,679
Republic Airways	61	82.3%	3.26%	6.7%	1,004,281
Delta Air Lines	71	82.1%	1.16%	6.3%	3,146,502
SkyWest Airlines	64	80.4%	1.33%	7.9%	2,433,643
Envoy Air	66	80.1%	1.80%	6.6%	886,878
United Airlines	66	79.7%	1.21%	7.5%	2,418,979
Alaska Airlines	71	78.9%	1.28%	5.0%	813,732
Southwest Airlines	71	78.2%	0.86%	6.0%	4,371,639
PSA Airlines	44	75.8%	3.43%	10.4%	717,562
Allegiant Air	58	75.7%	0.94%	9.5%	381,495
Spirit Airlines	54	75.5%	2.06%	9.6%	635,598
American Airlines	52	74.8%	1.76%	10.0%	3,019,376
JetBlue	45	72.5%	2.19%	11.7%	745,492
Frontier Airlines	45	71.8%	2.09%	11.5%	629,235

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Score is the FlyerIntel Airline Reliability Score. See all airlines ranked →

Data and methodology

Calculated by FlyerIntel from 3,146,502 Delta Air Lines flight records published by the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately, because folding them in would flatter a carrier that cancels rather than runs late. Figures below a published sample threshold are omitted rather than shown with a caveat.

Full methodology · Data sources · Report a problem

Analysis last recomputed September 26, 2026

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Delta Air Lines on-time performance, from FlyerIntel

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