Schedule: a typical summer Sunday (the flights of Jul 26, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3908
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
WN 3908 · STL → DCA
departs 7:50 PM CT · arrives 10:50 PM ET
Forecast issued Fri 11:00 AM ET · 58h before departure
Watch this flight
Other days
Today 55%
Sat 10/3 21%
Sun 10/4
Mon 10/5 25%
Wed 10/7 20%
Odds over time
Arrive at DCA more than 15 minutes late?
39%
chance · ±3 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
39%
Leave 15+ late
38%
Arrive 1h+ late
10%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
6.0d
Now
2d
1d
12h
6h
Departs
Lands
Arrive at DCA more than 15 minutes late?
Calm-weather odds: 28% · changed – in 24h
–
39%
Yes 39%
No 61%
Leave STL more than 15 minutes late?
Calm-weather odds: 34% · changed – in 24h
–
38%
Yes 38%
No 62%
Arrive at DCA more than an hour late?
Calm-weather odds: 6% · changed – in 24h
–
10%
Yes 10%
No 90%
Cancelled?
Calm-weather odds: <1% · changed – in 24h
–
<1%
Yes <1%
No 99%
How late will it get to DCA?
On time or early
61%
15–30 min late
10%
30 min–1 hour late
19%
1–2 hours late
7%
Over 2 hours late
3%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
Arrivals into DCA at that hour are often late
↑
Later flights pick up delays from earlier in the day
↑
Cloud base down to 500 ft, visibility down to 0.8 mi, 0.5 in of rain forecast at DCA that day
↓
Mostly benign weather forecast at STL
↓
Sundays in October are usually quieter than average
Weather at each end
STL (origin)
Gusts 10 kt Ceiling none (clear) Visibility 10+ mi Precip none
DCA (destination)
Gusts 9 kt Ceiling 500 ft Visibility 0.8 mi Precip 0.52 in
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.