IAH → ATL Flight Reliability

Right now

Origin · IAHNo disruption reported

Aviation weather is not currently a factor.

Updated 07:53 UTC

Houston airport profile →

Destination · ATLNo disruption reported

Aviation weather is not currently a factor.

Updated 07:52 UTC

Atlanta airport profile →

Route reliability

July 2023 – July 2026

Route Reliability Score

58/ 100Fair

Better than 31% of comparable major US routes (4,598 compared)

Calculated from 14,350 flights. How this is calculated

On-time arrivals

76.7%

10,808 of 14,089

Cancellation rate

1.67%

240 cancelled

Median arrival delay

-5 min

Average 10.4 min

Severe delays

8.7%

60+ minutes late

Delay when late

73 min

Average, when 15+ min late

Flights analyzed

14,350

4 carriers

IAH → ATL arrives on time 76.7% of the time; the return trip, ATL → IAH, arrives on time 75.4% of the time.

IAH → ATL spends 30.2 minutes on the ground on a 689-mile trip: 17.3 minutes from pushback to wheels-up at IAH and 13.0 minutes from touchdown to gate at ATL.

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

What stands out

This route has stayed remarkably steady year over year, a smaller swing than 98% of 5,368 comparable routes.

77.1% on time over the most recent 12 months (2025-08 to 2026-07), against 77.0% in the 12 months before (2024-08 to 2025-07), virtually unchanged.

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.

Why IAH → ATL flights are cancelled

July 2023 – July 2026

IAH → ATL cancelled 240 of 14,350 scheduled flights — about 1 in every 60. The reason filed most often was extreme weather, 49.2% of the cancellations coded on this route — about 1 in every 122 scheduled flights.

Share of cancellations

Weather49.2%

Airline46.7%

Air traffic4.2%

Security0.0%

Of 240 cancelled departures carrying a reason code.

What each reason means

Extreme weather1 in 122

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

118 cancellations, 49.2% of the total.

The airline1 in 128

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

112 cancellations, 46.7% of the total.

The air traffic system1 in 1,435

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

10 cancellations, 4.2% of the total.

Security—

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

0 cancellations, 0.0% of the total.

Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.

240 coded cancellations were recorded on IAH → ATL; the section appears from 50.

When it goes wrong

July 2023 – July 2026

One arrival in ten is worse than

51 min late

against a median of 5 min early

Arrived an hour or more late8.7%

Typical delay when late73 min

Cancelled1.67%

Landed somewhere else0.15%

Percentiles over 14,350 operations; cancelled and diverted flights are counted separately.

Will your connection be tight enough?

Layovers at ATL after arriving from IAH.

Connection buffer and chance of missing by layover length, IAH → ATL arrivals
Connection time	Chance of missing	Reads as
30 min	39%	Likely to miss
45 min	23%	High risk
60 min	15%	High risk
90 min	8.5%	Some risk
120 min	5.4%	Some risk

This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.67% of the time and diverts 0.15% of the time, which a late arrival never shows up in.

Chance of missing is the share of 14,089 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.

The worst tenth of arrivals on this route land at least 51 minutes late (90th-percentile gate arrival delay), over 14,350 operations.

Any other layover length: connection checker.

Best time to fly

IAH → ATL flights departing 5–9 AM arrived on time 85.8% of the time, against 58.7% for 9 PM–5 AM departures, a gap of 27.1 percentage points.

By day and hour

On-time arrival rate for each weekday and scheduled departure hour, in local time at the departure airport (IAH).

Hour of departure matters more than day of the week: hourly averages sit a typical 7.9 points from the route-wide rate, weekday averages 2.7 points.

On-time arrival rate for IAH to ATL by weekday and scheduled departure hour, local time. Each button reads out one slot.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
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

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

50–59
60–69
70–79
80–89
90–99

Fewer than 120 flights, not scored

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.

No slot is named best or worst: too few reach 500 flights. Departures before 6 AM and after 7 PM (1,931 flights) are not drawn: no slot in those hours has enough flights to score.

View as tableHide table

On-time arrival rate (%) with flights beneath, by scheduled departure hour and weekday for IAH to ATL. A dash means fewer than 120 flights, which are not scored.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
6 AM–7 AM	79.7% on time197 flights	86.2% on time151 flights	89.6% on time147 flights	89.0% on time200 flights	84.9% on time196 flights	76.8% on time195 flights	80.2% on time199 flights
7 AM–8 AM	86.2% on time293 flights	87.9% on time284 flights	91.5% on time285 flights	88.1% on time312 flights	85.9% on time307 flights	87.6% on time253 flights	85.4% on time292 flights
8 AM–9 AM	52 flights, too few to score	71 flights, too few to score	48 flights, too few to score	57 flights, too few to score	52 flights, too few to score	68 flights, too few to score	48 flights, too few to score
9 AM–10 AM	84.2% on time157 flights	87.1% on time140 flights	85.6% on time141 flights	79.5% on time147 flights	89.5% on time156 flights	85 flights, too few to score	80.3% on time148 flights
10 AM–11 AM	15 flights, too few to score	39 flights, too few to score	34 flights, too few to score	19 flights, too few to score	16 flights, too few to score	55 flights, too few to score	40 flights, too few to score
11 AM–12 PM	75.8% on time156 flights	80.3% on time147 flights	78.4% on time169 flights	78.8% on time168 flights	76.7% on time164 flights	80.1% on time159 flights	74.3% on time145 flights
12 PM–1 PM	71.5% on time151 flights	79.9% on time135 flights	117 flights, too few to score	83.3% on time138 flights	83.2% on time145 flights	101 flights, too few to score	75.6% on time131 flights
1 PM–2 PM	60 flights, too few to score	50 flights, too few to score	53 flights, too few to score	69 flights, too few to score	65 flights, too few to score	68 flights, too few to score	70 flights, too few to score
2 PM–3 PM	74.9% on time201 flights	77.1% on time180 flights	76.6% on time197 flights	75.0% on time202 flights	70.3% on time195 flights	78.9% on time156 flights	67.5% on time160 flights
3 PM–4 PM	86 flights, too few to score	84 flights, too few to score	80 flights, too few to score	88 flights, too few to score	94 flights, too few to score	70 flights, too few to score	87 flights, too few to score
4 PM–5 PM	68.9% on time125 flights	100 flights, too few to score	78 flights, too few to score	66.9% on time121 flights	117 flights, too few to score	64 flights, too few to score	118 flights, too few to score
5 PM–6 PM	102 flights, too few to score	96 flights, too few to score	101 flights, too few to score	108 flights, too few to score	101 flights, too few to score	100 flights, too few to score	112 flights, too few to score
6 PM–7 PM	65.7% on time253 flights	69.7% on time257 flights	75.0% on time250 flights	66.9% on time250 flights	67.1% on time245 flights	68.3% on time246 flights	59.3% on time235 flights

By departure window

5–9 AM85.8%

9 AM–12 PM80.4%

12–3 PM76.3%

3–6 PM68.1%

6–9 PM67.3%

9 PM–5 AM58.7%

By departure hour

12 AM

3 AM

6 AM

9 AM

12 PM

3 PM

6 PM

9 PM

Why IAH → ATL runs late

July 2023 – July 2026

Late-arriving aircraft42.7%

the inbound aircraft was late, so this flight started late

The airline29.7%

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

Air traffic control23.7%

airspace and airport capacity, including weather-driven flow control

Weather3.8%

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 IAH → ATL. Only delays of 15 minutes or more are attributed.

Late-arriving aircraft is the largest cause on IAH → ATL, at 42.7%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 85.8% of the time and 9 PM–5 AM departures 58.7%.

How this route holds up in bad weather

July 2023 – July 2026

Bad weather raises cancellations by a similar amount at both ends of IAH to ATL: 3.4 times the normal rate at IAH and 3.3 times at ATL. Cancelled in bad weather against normal hours: IAH 4.1% against 1.2%, ATL 3.4% against 1.0%. Flights that did leave IAH in bad weather arrived on time 63.8% of the time, against 78.6% in normal hours.

Bad weather and normal hours at the airports

Scheduled departures, July 2023 – July 2026

Departures from IAH and ATL in hours of bad weather and in normal hours
Departures from	IAH	ATL
Cancelled in bad weather	4.1%	3.4%
Cancelled in normal hours	1.2%	1.0%
Arrived on time, bad weather	63.8%	66.5%
Arrived on time, normal hours	78.6%	80.2%
Departures in bad weather	28,922	105,854

Of the carriers on this route, United Airlines (3.4% cancelled against 5.2% for the other carriers at IAH) cancelled the fewest departures from IAH in bad weather and Frontier Airlines (5.0% cancelled against 3.8% for the other carriers at IAH) the most.

This route’s airlines in bad weather at IAH

All departures from IAH

Cancellation rates in bad weather at IAH for the airlines that fly IAH to ATL, against the other carriers at IAH in the same months
Airline	Bad-weather departures	Cancelled	Other carriers
United Airlines	17,078	3.4%below the others	5.2%
Delta Air Lines	2,231	2.9%below the others	4.3%
Spirit Airlines	2,056	4.3%about level	4.4%
Frontier Airlines	915	5.0%above the others	3.8%

These are airport figures, not route figures: every scheduled departure from IAH and ATL, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from IAH on every route.

Weather source and limits. In full: IAH (airlines), ATL, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.

Airlines on this route

Carriers with at least 200 flights, by the airline that operated each one.

Airlines on this route
Carrier	Flights	On time	Cancelled	Median delay	Severe
Delta Air Lines	7,359	81.7%	1.54%	-7 min	6.5%
United Airlines	3,461	76.4%	1.01%	-4 min	9.1%
Frontier Airlines	1,727	59.4%	2.95%	5 min	16.6%
Spirit Airlines	1,673	72.2%	2.45%	-2 min	9.8%

Delta Air Lines flew 51.8% of the 14,220 flights listed. Frontier Airlines cancelled 2.95% of its flights here against 1.01% for United Airlines.

Delta Air Lines arrived on time 22.3 percentage points more often than Frontier Airlines on this route.

Flights on this route

Flight numbers with at least 600 operations here and still on the schedule.

Flights on this route
Flight	Scheduled	Operations	On time
DL1069 Delta Air Lines	6:00 AM	1,065	91.9%
DL1315 Delta Air Lines	7:05 AM	1,061	88.4%
DL1682 Delta Air Lines	11:49 AM	996	79.0%
DL1572 Delta Air Lines	3:59 PM	891	76.8%
F91404 Frontier Airlines	6:00 AM	702	66.6%

DL1069 (6:00 AM) arrived on time 91.9% of the time, 25.3 points more often than F91404 (6:00 AM) at 66.6%.

Weekly and seasonal patterns

By day of week

Mon74.7%

Tue78.7%

Wed81.6%

Thu76.9%

Fri75.9%

Sat77.3%

Sun72.4%

Wednesday is historically the most reliable day and Sunday the least, a gap of 9.2 percentage points.

By month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

May is historically the weakest month and September the strongest, a spread of 18.7 percentage points.

Reliability over time

July 2023 – July 2026

24

25

26

Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.1% against 77.0% in the 12 months before — broadly unchanged.

Data and methodology

Calculated by FlyerIntel from 14,350 IAH → ATL flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.

Full methodology · Data sources · Report a problem

Analysis last recomputed September 26, 2026

IAH airport ATL airport Return direction ATL → IAH

IAH→ATL

Right now

Route reliability

What stands out

Why IAH → ATL flights are cancelled

Share of cancellations

What each reason means

When it goes wrong

Will your connection be tight enough?

Best time to fly

By day and hour

By departure window

By departure hour

Why IAH → ATL runs late

How this route holds up in bad weather

Bad weather and normal hours at the airports

This route’s airlines in bad weather at IAH

Airlines on this route

Flights on this route

Weekly and seasonal patterns

By day of week

By month

Reliability over time

Data and methodology