Schedule: a typical Wednesday (the flights of Jul 29, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3981
SCHEDULED · TYPICAL SCHEDULE
Wednesday, September 30 Today
WN 3981 · STL → SEA
departs 12:10 PM CT · arrives 2:25 PM PT
Forecast issued Wed 9:00 AM ET · 4h before departure
Watch this flight
Other days
Today
Thu 10/1 23%
Fri 10/2 23%
Sat 10/3 23%
Sun 10/4 26%
Mon 10/5 21%
Tue 10/6 21%
Odds over time
Arrive at SEA more than 15 minutes late?
26%
chance · ±0 pts
+3 pts · 24h
HOW SURE WE ARE
High. The odds now come mostly from live FAA and airport data.
Arrive 15+ late
26%
Leave 15+ late
21%
Arrive 1h+ late
2%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.7d
2d
1d
12h
6h
Now
Departs
Lands
Arrive at SEA more than 15 minutes late?
Calm-weather odds: 22% · changed +3 pts in 24h
+3 pts
26%
Yes 26%
No 74%
Leave STL more than 15 minutes late?
Calm-weather odds: 18% · changed +5 pts in 24h
+5 pts
21%
Yes 21%
No 79%
Arrive at SEA more than an hour late?
Calm-weather odds: 3% · changed −2 pts in 24h
−2 pts
2%
Yes 2%
No 98%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 100%
How late will it get to SEA?
On time or early
73%
15–30 min late
15%
30 min–1 hour late
9%
1–2 hours late
<1%
Over 2 hours late
1%
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 36% of the time recently
↑
SEA is prone to delays
↑
12pm departures from STL are often late
↓
Wednesdays in September are usually quieter than average
↓
Mostly benign weather forecast at SEA
Weather at each end
STL (origin)
Gusts 14 kt Ceiling 9,000 ft Visibility 10+ mi Precip none
SEA (destination)
Gusts 10 kt Ceiling 3,200 ft Visibility 10+ 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.