Denver (DEN) to San Diego (SAN): On-Time Performance
Data through May 2026
The calendar drives reliability on DEN–SAN. February 2026 flights landed on schedule 84% of the time, but July 2025 dropped to 65% — a gap of 19 points. Across the full period the route averages 76% on-time against a national 78%. Morning departures also hold up better than evening ones (84% vs 64%), which matters most in the rough months.
- On-time
- 76%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 0.8%
- Flights/day
- 16
- last 12 months
- Duration
- 2h 28m
- scheduled
- Distance
- 853 mi
Best airline from DEN to SAN
5 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Alaska Airlinesmost reliable | 82% | 11 min | 1.3% | 391 |
| United Airlines | 80% | 13 min | 0.6% | 4,269 |
| SkyWest Airlines | 78% | 10 min | 1.0% | 295 |
| Frontier Airlines | 75% | 17 min | 1.6% | 1,654 |
| Southwest Airlines | 72% | 16 min | 0.7% | 4,785 |
Monthly on-time trend
Best time to fly from DEN to SAN
Aim for departures around 5 a.m. (90% on-time); avoid 8 p.m. departures (60%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 77% | 13 min |
| Tuesdaybest | 80% | 13 min |
| Wednesday | 79% | 12 min |
| Thursday | 72% | 19 min |
| Friday | 72% | 19 min |
| Saturday | 79% | 11 min |
| Sunday | 73% | 15 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft44%
- Airline operations29%
- National airspace system24%
- Weather4%
Frequently asked questions
- How often are flights from DEN to SAN delayed?
- 24% of DEN–SAN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 15 minutes.
- Which airline is most reliable from DEN to SAN?
- Alaska Airlines has the best on-time record on this route at 82%, based on 391 flights. 5 airlines flew DEN–SAN frequently enough to compare in this period.
- What is the best time of day to fly from DEN to SAN?
- Departures around 5 a.m. have the best record (90% on-time), while departures around 8 p.m. have the worst (60%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DEN to SAN?
- The scheduled DEN–SAN flight time averages 2h 28m over 853 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
- How often are DEN to SAN flights cancelled?
- 0.8% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from DEN to SAN?
- July 2025 was the roughest month in this dataset, with only 65% of arrivals on time. The best was February 2026 at 84%. If your dates are flexible, that 19-point gap is worth planning around.
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Based on 11,394 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.