Schedule: a typical Thursday (the flights of Jul 30, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SKYWEST · FLIGHT OO 3991
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1 Today
OO 3991 · SEA → SFO
departs 5:50 PM PT · arrives 8:16 PM PT
Forecast issued Thu 7:00 PM ET · 2h before departure
Watch this flight
Other days
Today
Fri 10/2 24%
Sat 10/3 22%
Sun 10/4 31%
Mon 10/5 27%
Tue 10/6 20%
Wed 10/7 19%
Odds over time
Arrive at SFO more than 15 minutes late?
40%
chance · ±0 pts
+7 pts · 24h
HOW SURE WE ARE
High. The odds now come mostly from live FAA and airport data.
Arrive 15+ late
40%
Leave 15+ late
36%
Arrive 1h+ late
24%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
1d
12h
6h
Now
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 33% · changed +7 pts in 24h
+7 pts
40%
Yes 40%
No 60%
Leave SEA more than 15 minutes late?
Calm-weather odds: 30% · changed +4 pts in 24h
+4 pts
36%
Yes 36%
No 64%
Arrive at SFO more than an hour late?
Calm-weather odds: 10% · changed +13 pts in 24h
+13 pts
24%
Yes 24%
No 76%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to SFO?
On time or early
59%
15–30 min late
24%
30 min–1 hour late
0%
1–2 hours late
10%
Over 2 hours late
6%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
Arrivals into SFO at that hour are often late
↑
This flight has been late 33% of the time recently
↑
5pm departures from SEA are often late
↓
Cloud base down to 500 ft forecast at SFO that day
↓
Mostly benign weather forecast at SEA
Weather at each end
SEA (origin)
Gusts 9 kt Ceiling 5,500 ft Visibility 10+ mi Precip none
SFO (destination)
Gusts 11 kt Ceiling 500 ft Visibility 6 mi Precip none
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.