San Diego (SAN) to Denver (DEN): On-Time Performance
Data through May 2026
When you fly SAN to DEN matters as much as anything else about the booking: the route swung from 87% on-time in January 2026 to just 63% in June 2025. Across the full period the route averages 78% on-time against a national 78%. Morning departures also hold up better than evening ones (85% vs 74%), which matters most in the rough months.
- On-time
- 78%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 0.9%
- Flights/day
- 16
- last 12 months
- Duration
- 2h 28m
- scheduled
- Distance
- 853 mi
Best airline from SAN to DEN
5 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 83% | 12 min | 0.7% | 4,269 |
| Alaska Airlines | 82% | 11 min | 1.3% | 390 |
| SkyWest Airlines | 81% | 10 min | 1.7% | 295 |
| Southwest Airlines | 74% | 17 min | 0.8% | 4,798 |
| Frontier Airlines | 74% | 20 min | 1.5% | 1,654 |
Monthly on-time trend
Best time to fly from SAN to DEN
Aim for departures around 6 a.m. (88% on-time); avoid 3 p.m. departures (63%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 77% | 16 min |
| Tuesday | 82% | 12 min |
| Wednesday | 81% | 11 min |
| Thursday | 74% | 18 min |
| Friday | 71% | 21 min |
| Saturdaybest | 84% | 10 min |
| Sunday | 77% | 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 aircraft49%
- Airline operations19%
- National airspace system30%
- Weather2%
Frequently asked questions
- How often are flights from SAN to DEN delayed?
- 22% of SAN–DEN 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 SAN to DEN?
- United Airlines has the best on-time record on this route at 83%, based on 4,269 flights. 5 airlines flew SAN–DEN frequently enough to compare in this period.
- What is the best time of day to fly from SAN to DEN?
- Departures around 6 a.m. have the best record (88% on-time), while departures around 3 p.m. have the worst (63%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SAN to DEN?
- The scheduled SAN–DEN flight time averages 2h 28m over 853 miles. Actual arrival times vary — flights on this route land 15+ minutes late 22% of the time.
- How often are SAN to DEN flights cancelled?
- 0.9% 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 SAN to DEN?
- June 2025 was the roughest month in this dataset, with only 63% of arrivals on time. The best was January 2026 at 87%. If your dates are flexible, that 24-point gap is worth planning around.
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Based on 11,406 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.