San Diego (SAN) to Boston (BOS): On-Time Performance
Data through May 2026
When you fly SAN to BOS matters as much as anything else about the booking: the route swung from 90% on-time in May 2026 to just 63% in July 2024. Across the full period the route averages 76% on-time against a national 78%.
- On-time
- 76%
- arrived <15 min late
- Avg delay
- 20 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 4.9
- last 12 months
- Duration
- 5h 38m
- scheduled
- Distance
- 2,588 mi
Best airline from SAN to BOS
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 79% | 19 min | 1.5% | 728 |
| JetBlue Airways | 76% | 21 min | 1.0% | 1,671 |
| Alaska Airlines | 73% | 18 min | 0.9% | 948 |
Monthly on-time trend
Best time to fly from SAN to BOS
Aim for departures around 9 p.m. (85% on-time); avoid 11 a.m. departures (68%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 78% | 20 min |
| Tuesdaybest | 80% | 13 min |
| Wednesday | 78% | 16 min |
| Thursday | 71% | 24 min |
| Friday | 73% | 24 min |
| Saturday | 80% | 16 min |
| Sunday | 72% | 24 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 operations24%
- National airspace system36%
- Weather9%
Frequently asked questions
- How often are flights from SAN to BOS delayed?
- 24% of SAN–BOS 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 20 minutes.
- Which airline is most reliable from SAN to BOS?
- Delta Air Lines has the best on-time record on this route at 79%, based on 728 flights. 3 airlines flew SAN–BOS frequently enough to compare in this period.
- What is the best time of day to fly from SAN to BOS?
- Departures around 9 p.m. have the best record (85% on-time), while departures around 11 a.m. have the worst (68%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SAN to BOS?
- The scheduled SAN–BOS flight time averages 5h 38m over 2,588 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
- How often are SAN to BOS flights cancelled?
- 1.1% 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 BOS?
- July 2024 was the roughest month in this dataset, with only 63% of arrivals on time. The best was May 2026 at 90%. If your dates are flexible, that 27-point gap is worth planning around.
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Based on 3,347 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.