Schedule: a typical Tuesday (the flights of Jul 28, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3936
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Yesterday
WN 3936 · STL → LAS
departs 9:15 PM CT · arrives 10:45 PM PT
Forecast issued Tue 10:00 PM ET · 0h before departure
Watch this flight
Other days
Tue 9/29
Today 19%
Thu 10/1 30%
Fri 10/2 25%
Sun 10/4 22%
Mon 10/5 17%
Tue 10/6 13%
Odds over time
Arrive at LAS more than 15 minutes late?
31%
chance · ±2 pts
+6 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
31%
Leave 15+ late
40%
Arrive 1h+ late
9%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
1d
12h
6h
Departs
Lands
Arrive at LAS more than 15 minutes late?
Calm-weather odds: 33% · changed +6 pts in 24h
+6 pts
31%
Yes 31%
No 69%
Leave STL more than 15 minutes late?
Calm-weather odds: 40% · changed +9 pts in 24h
+9 pts
40%
Yes 40%
No 60%
Arrive at LAS more than an hour late?
Calm-weather odds: 9% · changed +5 pts in 24h
+5 pts
9%
Yes 9%
No 91%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to LAS?
On time or early
68%
15–30 min late
14%
30 min–1 hour late
8%
1–2 hours late
8%
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
↑
9pm departures from STL are often late
↑
LAS is prone to delays
↑
This flight has been late 35% of the time recently
↓
Tuesdays in September are usually quieter than average
↓
Mostly benign weather forecast at STL
Weather at each end
STL (origin)
Gusts 9 kt Ceiling none (clear) Visibility 10+ mi Precip none
LAS (destination)
Gusts 27 kt Ceiling 4,700 ft Visibility 7 mi Precip 0.08 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.