Schedule: a typical Friday (the flights of Jul 31, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.

SKYWEST · FLIGHT OO 3991 SCHEDULED · TYPICAL SCHEDULE

Friday, October 2 Tomorrow

OO 3991 · SEA → SFO

departs 5:50 PM PT · arrives 8:16 PM PT

Forecast issued Thu 4:00 PM ET · 29h before departure

Arrive at SFO more than 15 minutes late?

20% chance · ±3 pts −6 pts · 24h

HOW SURE WE ARE Moderate. The odds now blend history with early weather forecasts.

How late will it get to SFO?

On time or early
79%
15–30 min late
9%
30 min–1 hour late
4%
1–2 hours late
3%
Over 2 hours late
5%
Cancelled
<1%

Gate arrival compared with the scheduled arrival. The ranges add up to 100%.

What’s moving the odds

↑ This flight has been late 33% of the time recently

↑ Arrivals into SFO at that hour are often late

↑ 5pm departures from SEA are often late

↓ Mostly benign weather forecast at SFO

↓ Mostly benign weather forecast at SEA

Weather at each end

SEA (origin) Gusts8 kt Ceilingnone (clear) Visibility10+ mi Precipnone

SFO (destination) Gusts8 kt Ceiling500 ft Visibility6 mi Precipnone

How this resolves

Yes if the gate arrival is more than 15 minutes after the scheduled arrival. Cancelled or diverted flights resolve N/A.

Every question here is display only — there is no betting or money involved. Gate times come from the airline; a cancellation resolves only the “Cancelled?” question, and a diversion voids the delay questions.

OO 3991 · SEA → SFO

Odds over time

How late will it get to SFO?