FlyerIntel

Route profile

DEN→SAN

Flight reliability, delays and best times to fly from Denver to San Diego, 853 miles.

Right now

Origin · DENNo disruption reported

Aviation weather is not currently a factor.

Updated

Denver airport profile →

Destination · SANNo disruption reported

Aviation weather is not currently a factor.

Updated

San Diego airport profile →

Route reliability

July 2023 – July 2026

Route Reliability Score
65/ 100Good

Better than 47% of comparable major US routes (4,598 compared)

Calculated from 17,468 flights. How this is calculated

On-time arrivals
75.5%
13,020 of 17,242
Cancellation rate
0.98%
171 cancelled
Median arrival delay
-4 min
Average 7.1 min
Severe delays
7.4%
60+ minutes late
Delay when late
56 min
Average, when 15+ min late
Flights analyzed
17,468
5 carriers

DEN → SAN arrives on time 75.5% of the time; the return trip, SAN → DEN, arrives on time 78.9% of the time, a 3.4-point gap between the two directions of the same city pair.

DEN → SAN spends 22.9 minutes on the ground on an 853-mile trip: 17.6 minutes from pushback to wheels-up at DEN and 5.3 minutes from touchdown to gate at SAN.

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 92% of 5,368 comparable routes.

75.4% on time over the most recent 12 months (2025-08 to 2026-07), against 75.9% 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 DEN → SAN flights are cancelled

July 2023 – July 2026

DEN → SAN cancelled 171 of 17,468 scheduled flights — about 1 in every 102. The reason filed most often was extreme weather, 45.0% of the cancellations coded on this route — about 1 in every 227 scheduled flights.

Share of cancellations

Weather45.0%
Airline38.0%
Air traffic17.0%
Security0.0%

Of 171 cancelled departures carrying a reason code.

What each reason means

Extreme weather1 in 227

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

77 cancellations, 45.0% of the total.

The airline1 in 269

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

65 cancellations, 38.0% of the total.

The air traffic system1 in 602

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

29 cancellations, 17.0% 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.

171 coded cancellations were recorded on DEN → SAN; the section appears from 50.

When it goes wrong

July 2023 – July 2026

One arrival in ten is worse than

47 min late

against a median of 4 min early

Arrived an hour or more late7.4%
Typical delay when late56 min
Cancelled0.98%
Landed somewhere else0.31%

Percentiles over 17,468 operations; cancelled and diverted flights are counted separately.

Will your connection be tight enough?

Layovers at SAN after arriving from DEN.

Connection buffer and chance of missing by layover length, DEN → SAN arrivals
Connection timeChance of missingReads as
30 min42%Likely to miss
45 min24%High risk
60 min15%High risk
90 min7.3%Some risk
120 min3.9%Low 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 0.98% of the time and diverts 0.31% of the time, which a late arrival never shows up in.

Chance of missing is the share of 17,242 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 47 minutes late (90th-percentile gate arrival delay), over 17,468 operations.

Any other layover length: connection checker.

Best time to fly

DEN → SAN flights departing 5–9 AM arrived on time 88.4% of the time, against 62.8% for 6–9 PM departures, a gap of 25.6 percentage points.

By day and hour

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

Hour of departure matters more than day of the week: hourly averages sit a typical 9.6 points from the route-wide rate, weekday averages 3.2 points.

On-time arrival rate for DEN to SAN by weekday and scheduled departure hour, local time. Each button reads out one slot.
HourMondayTuesdayWednesdayThursdayFridaySaturdaySunday
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

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

  • 40–49
  • 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 11 PM (246 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 DEN to SAN. A dash means fewer than 120 flights, which are not scored.
HourMondayTuesdayWednesdayThursdayFridaySaturdaySunday
6 AM–7 AM92.2% on time170 flights113 flights, too few to score110 flights, too few to score92.0% on time166 flights88.0% on time167 flights85 flights, too few to score116 flights, too few to score
7 AM–8 AM91.8% on time208 flights93.6% on time202 flights92.4% on time199 flights86.6% on time212 flights85.4% on time220 flights89.5% on time240 flights86.1% on time238 flights
8 AM–9 AM83.1% on time180 flights90.1% on time143 flights89.9% on time142 flights87.2% on time175 flights87.1% on time164 flights81.8% on time132 flights84.6% on time157 flights
9 AM–10 AM93 flights, too few to score113 flights, too few to score95 flights, too few to score98 flights, too few to score89 flights, too few to score100 flights, too few to score81 flights, too few to score
10 AM–11 AM98 flights, too few to score100 flights, too few to score119 flights, too few to score96 flights, too few to score89 flights, too few to score76 flights, too few to score90 flights, too few to score
11 AM–12 PM79.0% on time273 flights88.1% on time238 flights77.7% on time239 flights74.3% on time253 flights70.3% on time274 flights82.5% on time191 flights81.8% on time221 flights
12 PM–1 PM82 flights, too few to score77 flights, too few to score86 flights, too few to score96 flights, too few to score87 flights, too few to score97 flights, too few to score107 flights, too few to score
1 PM–2 PM85.2% on time210 flights84.0% on time252 flights85.0% on time251 flights81.3% on time210 flights73.9% on time201 flights83.9% on time186 flights85.5% on time232 flights
2 PM–3 PM65 flights, too few to score32 flights, too few to score35 flights, too few to score68 flights, too few to score71 flights, too few to score65 flights, too few to score56 flights, too few to score
3 PM–4 PM74.0% on time149 flights78.6% on time145 flights78.7% on time165 flights75.0% on time136 flights72.3% on time142 flights81.8% on time138 flights76.9% on time137 flights
4 PM–5 PM68.1% on time163 flights77.2% on time146 flights76.4% on time161 flights66.9% on time155 flights68.1% on time167 flights74.9% on time177 flights75.0% on time164 flights
5 PM–6 PM88 flights, too few to score101 flights, too few to score83 flights, too few to score95 flights, too few to score92 flights, too few to score47 flights, too few to score102 flights, too few to score
6 PM–7 PM62.9% on time126 flights84 flights, too few to score79 flights, too few to score106 flights, too few to score49.2% on time123 flights87 flights, too few to score83 flights, too few to score
7 PM–8 PM61.3% on time245 flights67.6% on time226 flights72.1% on time225 flights57.1% on time261 flights65.8% on time250 flights66.8% on time230 flights57.0% on time299 flights
8 PM–9 PM66.0% on time145 flights68.0% on time125 flights67.6% on time152 flights60.5% on time129 flights66.9% on time139 flights69.7% on time123 flights101 flights, too few to score
9 PM–10 PM63.2% on time164 flights68.1% on time136 flights68.2% on time199 flights62.4% on time174 flights64.2% on time189 flights107 flights, too few to score57.2% on time207 flights
10 PM–11 PM73.1% on time135 flights94 flights, too few to score76 flights, too few to score64.7% on time140 flights74.2% on time136 flights98 flights, too few to score64.1% on time145 flights

By departure window

5–9 AM88.4%
9 AM–12 PM79.2%
12–3 PM79.3%
3–6 PM71.9%
6–9 PM62.8%
9 PM–5 AM66.5%

By departure hour

  • 12 AM to 4 AM: too few flights to score
  • 5 AM: 85.9% on time from 238 flights
  • 6 AM: 90.3% on time from 927 flights
  • 7 AM: 89.2% on time from 1,519 flights
  • 8 AM: 86.2% on time from 1,093 flights
  • 9 AM: 79.8% on time from 669 flights
  • 10 AM: 79.5% on time from 668 flights
  • 11 AM: 78.8% on time from 1,689 flights
  • 12 PM: 76.5% on time from 632 flights
  • 1 PM: 82.8% on time from 1,542 flights
  • 2 PM: 70.2% on time from 392 flights
  • 3 PM: 76.8% on time from 1,012 flights
  • 4 PM: 72.3% on time from 1,133 flights
  • 5 PM: 63.1% on time from 608 flights
  • 6 PM: 58.6% on time from 688 flights
  • 7 PM: 63.6% on time from 1,736 flights
  • 8 PM: 64.6% on time from 914 flights
  • 9 PM: 63.5% on time from 1,176 flights
  • 10 PM: 70.8% on time from 824 flights
  • 11 PM: too few flights to score

Why DEN → SAN runs late

July 2023 – July 2026

Late-arriving aircraft44.7%

the inbound aircraft was late, so this flight started late

The airline30.0%

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

Air traffic control21.8%

airspace and airport capacity, including weather-driven flow control

Weather3.4%

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 DEN → SAN. Only delays of 15 minutes or more are attributed.

Late-arriving aircraft is the largest cause on DEN → SAN, at 44.7%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 88.4% of the time and 6–9 PM departures 62.8%.

How this route holds up in bad weather

July 2023 – July 2026

Bad weather raises cancellations by a similar amount at both ends of DEN to SAN: 4.0 times the normal rate at DEN and 3.5 times at SAN. Cancelled in bad weather against normal hours: DEN 2.8% against 0.7%, SAN 3.5% against 1.0%. Flights that did leave DEN in bad weather arrived on time 51.5% of the time, against 78.8% in normal hours.

Bad weather and normal hours at the airports

Scheduled departures, July 2023 – July 2026
Departures from DEN and SAN in hours of bad weather and in normal hours
Departures fromDENSAN
Cancelled in bad weather2.8%3.5%
Cancelled in normal hours0.7%1.0%
Arrived on time, bad weather51.5%66.7%
Arrived on time, normal hours78.8%78.4%
Departures in bad weather92,61019,707

Of the carriers on this route, United Airlines (1.5% cancelled against 3.5% for the other carriers at DEN) cancelled the fewest departures from DEN in bad weather and SkyWest Airlines (5.8% cancelled against 1.8% for the other carriers at DEN) the most.

This route’s airlines in bad weather at DEN

All departures from DEN
Cancellation rates in bad weather at DEN for the airlines that fly DEN to SAN, against the other carriers at DEN in the same months
AirlineBad-weather departuresCancelledOther carriers
United Airlines30,8531.5%below the others3.5%
Alaska Airlines6411.4%below the others2.7%
Southwest Airlines28,4672.4%below the others3.1%
Frontier Airlines6,7403.1%about level2.8%
SkyWest Airlines19,2755.8%above the others1.8%

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

Weather source and limits. In full: DEN (airlines), SAN, 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
CarrierFlightsOn timeCancelledMedian delaySevere
Southwest Airlines7,42571.5%0.79%0 min8.0%
United Airlines6,59780.1%0.85%-7 min6.9%
Frontier Airlines2,57774.6%1.71%-6 min8.0%
Alaska Airlines49583.6%1.21%-11 min4.9%
SkyWest Airlines37470.9%1.60%-3 min6.8%

Southwest Airlines flew 42.5% of the 17,468 flights listed.

Alaska Airlines arrived on time 12.7 percentage points more often than SkyWest 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
FlightScheduledOperationsOn time
UA1281 United Airlines3:55 PM1,06182.2%
UA2309 United Airlines7:45 AM1,04987.6%
UA540 United Airlines7:40 PM1,03968.9%
UA1302 United Airlines1:25 PM68987.1%
F92817 Frontier Airlines5:35 AM65382.5%
F94989 Frontier Airlines10:29 PM62370.1%

UA2309 (7:45 AM) arrived on time 87.6% of the time, 18.7 points more often than UA540 (7:40 PM) at 68.9%.

Weekly and seasonal patterns

By day of week

Mon75.8%
Tue80.3%
Wed79.1%
Thu72.2%
Fri72.1%
Sat77.6%
Sun72.5%

Tuesday is historically the most reliable day and Friday the least, a gap of 8.2 percentage points.

By month

  • Jan: 80.2%
  • Feb: 76.7%
  • Mar: 81.3%
  • Apr: 79.4%
  • May: 75.3%
  • Jun: 65.9%
  • Jul: 64.4%
  • Aug: 73.4%
  • Sep: 77.5%
  • Oct: 76.0%
  • Nov: 81.8%
  • Dec: 79.6%

July is historically the weakest month and November the strongest, a spread of 17.4 percentage points.

Reliability over time

July 2023 – July 2026

  • July 2023: 61.4% from 491 flights
  • August 2023: 74.1% from 482 flights
  • September 2023: 75.4% from 446 flights
  • October 2023: 78.0% from 479 flights
  • November 2023: 87.7% from 462 flights
  • December 2023: 90.2% from 448 flights
  • January 2024: 78.5% from 401 flights
  • February 2024: 72.2% from 390 flights
  • March 2024: 78.2% from 448 flights
  • April 2024: 77.0% from 461 flights
  • May 2024: 74.5% from 497 flights
  • June 2024: 67.5% from 516 flights
  • July 2024: 66.5% from 499 flights
  • August 2024: 76.3% from 481 flights
  • September 2024: 83.9% from 459 flights
  • October 2024: 76.7% from 495 flights
  • November 2024: 78.5% from 459 flights
  • December 2024: 79.5% from 452 flights
  • January 2025: 79.8% from 427 flights
  • February 2025: 72.4% from 383 flights
  • March 2025: 83.0% from 449 flights
  • April 2025: 76.6% from 434 flights
  • May 2025: 73.8% from 458 flights
  • June 2025: 65.4% from 458 flights
  • July 2025: 65.1% from 458 flights
  • August 2025: 69.6% from 436 flights
  • September 2025: 72.7% from 411 flights
  • October 2025: 73.4% from 532 flights
  • November 2025: 79.5% from 529 flights
  • December 2025: 70.7% from 538 flights
  • January 2026: 81.9% from 500 flights
  • February 2026: 84.1% from 460 flights
  • March 2026: 82.6% from 537 flights
  • April 2026: 84.0% from 508 flights
  • May 2026: 77.2% from 515 flights
  • June 2026: 65.0% from 525 flights
  • July 2026: 64.4% from 544 flights

Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 75.4% against 75.9% in the 12 months before — broadly unchanged.

Data and methodology

Calculated by FlyerIntel from 17,468 DEN → SAN 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

Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports

Analysis last recomputed

DEN airportSAN airportReturn direction SAN → DEN