DL3991Delta Air Lines · SFO → SEA
live · 17m ago
Route confirmed Delta Air Lines

DL3991 San FranciscoSFO · 20:58 SeattleSEA · 23:13

DL3991 by Delta Air Lines flies from San Francisco (SFO) to Seattle (SEA).

Right nowNext departure today Operates daily
20:58

scheduled from SFO

The route today

live boards
SFOSan FranciscoOn-time likelySFO delay board →
SEASeattleModerate riskSEA delay board →
SFO→SEAevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
42%Chance of 15+ min delay
1.2%Chance of cancellation
+11 minTypical airport delay in this weather

Conditions at SFO and SEA are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. These figures come from both airports' records under conditions like today's, over the last 90 days.

Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →

Tomorrow at San Francisco

Forecast

Wed 4 Nov, local date

High19°Clikely 18°C to 20°C
Low12°Clikely 10°C to 14°C

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

Tomorrow at Seattle

Forecast

Wed 4 Nov, local date

High14°Clikely 12°C to 15°C
Low6°Clikely 4°C to 7°C
  • 32% chance of fog
  • 86% chance of rain

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other San Francisco to Seattle flights today

same route · Delta Air Lines
DL2721departs 06:20
DL1134departs 10:35
DL2870departs 10:40
DL1412departs 14:15

If DL3991 is cancelled, these are the other Delta Air Lines nonstop flights from San Francisco to Seattle on the same day, with scheduled departure times in SFO local time. Most flights that show a delay still operate. Rebooking usually helps only when that delay is very large. Every airline on this route →

How DL3991 actually runs

Pro Flight Search has tracked every published board update for DL3991 across the SFO and SEA boards: schedule changes, gate pushes and actual clocks. Early read: no clear pattern yet. Only 1 completed leg so far: departed +9 min. Not enough to call it.

The verdict above is that record speaking, so it reflects how DL3991 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Technical record

How this operation is measured

board clocks

Board log

scheduled → actual, per operation
10-30SFO 20:58 21:07 (+9)SEA 23:13
10-29SFO 20:58SEA 23:13

Board clocks recorded as SFO and SEA published them.

Planning around DL3991? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search: DL3991 San Francisco to Seattle on-time performance, measured from the SFO and SEA airport boards.

Canonical URL
https://proflightsearch.com/flight/DL3991
How we measure this →