Flight history · Aug 2025 – Jul 2026 · US DOT on-time records
DL 3991 · Seattle (SEA) → San Francisco (SFO)
Sold by Delta, flown by SkyWest. Still flying: 56 of the last 56 days (Daily).
Arrives on time65%within 15 minutes, of 294 flights
Cancelled0.7%of scheduled flights
An hour or more late10%of flights that operated
When late, on average56 minlate, among flights 15+ min late
Schedule
Typical times in the Jun 6 – Jul 31, 2026 schedule, local at each airport.
- Leaves SEA
- 17:52
- Arrives SFO
- 20:19
- Flight time
- 2h 27m
- Days flown, last 8 weeks
- 56 of 56
Each square is a day, Sat Jun 6 to Fri Jul 31, two weeks per row (each column is the same weekday); filled = flew.
How late it arrives
Share of flights that operated arriving more than this late.
Horizontal: minutes late at arrival (0 to 3 hours). Vertical: share of flights later than that.
Its hour at SEA
All flights leaving Seattle (SEA) at 5–6 pm, wherever they’re going: 77% left within 15 minutes and 0.9% were cancelled (12,513 flights in the year). Other Delta flights on this route →
Upcoming forecasts
Our odds that this flight is late or cancelled on the days we publish.