Washington (IAD) to San Diego (SAN): On-Time Performance
Data through May 2026
When you fly IAD to SAN matters as much as anything else about the booking: the route swung from 91% on-time in August 2025 to just 71% in February 2025. Across the full period the route averages 81% on-time against a national 78%. Morning departures also hold up better than evening ones (92% vs 72%), which matters most in the rough months.
- On-time
- 81%
- arrived <15 min late
- Avg delay
- 13 min
- completed flights
- Cancelled
- 0.4%
- Flights/day
- 3.8
- last 12 months
- Duration
- 5h 34m
- scheduled
- Distance
- 2,253 mi
Best airline from IAD to SAN
2 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 83% | 12 min | 0.4% | 2,134 |
| Alaska Airlines | 73% | 15 min | 0.3% | 723 |
Monthly on-time trend
Best time to fly from IAD to SAN
Aim for departures around 9 a.m. (95% on-time); avoid 6 p.m. departures (69%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 83% | 11 min |
| Tuesdaybest | 84% | 9 min |
| Wednesday | 76% | 14 min |
| Thursday | 79% | 15 min |
| Friday | 79% | 14 min |
| Saturday | 83% | 13 min |
| Sunday | 80% | 12 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft31%
- Airline operations27%
- National airspace system32%
- Weather10%
Frequently asked questions
- How often are flights from IAD to SAN delayed?
- 19% of IAD–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 13 minutes.
- Which airline is most reliable from IAD to SAN?
- United Airlines has the best on-time record on this route at 83%, based on 2,134 flights. 2 airlines flew IAD–SAN frequently enough to compare in this period.
- What is the best time of day to fly from IAD to SAN?
- Departures around 9 a.m. have the best record (95% on-time), while departures around 6 p.m. have the worst (69%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from IAD to SAN?
- The scheduled IAD–SAN flight time averages 5h 34m over 2,253 miles. Actual arrival times vary — flights on this route land 15+ minutes late 19% of the time.
- How often are IAD to SAN flights cancelled?
- 0.4% 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 IAD to SAN?
- February 2025 was the roughest month in this dataset, with only 71% of arrivals on time. The best was August 2025 at 91%. If your dates are flexible, that 21-point gap is worth planning around.
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Based on 2,857 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.