San Diego (SAN) to Denver (DEN): On-Time Performance
Data through July 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 77% 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
- 77%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 0.9%
- Flights/day
- 17
- last 12 months
- Duration
- 2h 28m
- scheduled
- Distance
- 853 mi
Best airline from SAN to DEN
5 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Alaska Airlinesmost reliable | 85% | 9 min | 1.0% | 495 |
| United Airlines | 83% | 11 min | 0.6% | 4,416 |
| Frontier Airlines | 75% | 19 min | 1.4% | 1,678 |
| SkyWest Airlines | 75% | 13 min | 2.1% | 373 |
| Southwest Airlines | 73% | 17 min | 0.8% | 4,997 |
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 (61%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 77% | 16 min |
| Tuesday | 81% | 12 min |
| Wednesday | 80% | 12 min |
| Thursday | 73% | 19 min |
| Friday | 71% | 20 min |
| Saturdaybest | 85% | 10 min |
| Sunday | 77% | 14 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 operations20%
- National airspace system29%
- Weather2%
Frequently asked questions
- How often are flights from SAN to DEN delayed?
- 23% of SAN–DEN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 15 minutes.
- Which airline is most reliable from SAN to DEN?
- Alaska Airlines has the best on-time record on this route at 85%, based on 495 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 (61%). 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 23% of the time.
- How often are SAN to DEN flights cancelled?
- 0.9% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, 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 11,959 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.