Schedule: a typical Saturday (the flights of Jul 25, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3934
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3
WN 3934 · STL → LAS
departs 5:30 AM CT · arrives 6:55 AM PT
Forecast issued Wed 1:00 PM ET · 66h before departure
Watch this flight
Other days
Today 4%
Thu 10/1 4%
Fri 10/2 7%
Sat 10/3
Mon 10/5 5%
Tue 10/6 3%
Odds over time
Arrive at LAS more than 15 minutes late?
3%
chance · ±1 pts
+0 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
3%
Leave 15+ late
5%
Arrive 1h+ late
<1%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
3%
6%
9%
12%
4.4d
Now
2d
1d
12h
6h
Departs
Lands
Arrive at LAS more than 15 minutes late?
Calm-weather odds: 3% · changed +0 pts in 24h
+0 pts
3%
Yes 3%
No 97%
Leave STL more than 15 minutes late?
Calm-weather odds: 3% · changed +1 pt in 24h
+1 pt
5%
Yes 5%
No 95%
Arrive at LAS more than an hour late?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
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
96%
15–30 min late
2%
30 min–1 hour late
<1%
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
↑
LAS is prone to delays
↓
Early flights usually leave on time
↓
5am departures from STL are usually not late
Weather at each end
STL (origin)
Gusts 10 kt Ceiling none (clear) Visibility 10+ mi Precip none
LAS (destination)
Gusts 4 kt Ceiling none (clear) 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.