Schedule: a typical summer Saturday (the flights of Jul 25, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3858
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3 Tomorrow
WN 3858 · SFO → STL
departs 10:25 AM PT · arrives 4:15 PM CT
Forecast issued Fri 4:00 PM ET · 21h before departure
Watch this flight
Odds over time
Arrive at STL more than 15 minutes late?
23%
chance · ±1 pts
−2 pts · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
23%
Leave 15+ late
22%
Arrive 1h+ late
4%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
4.6d
2d
Now
12h
6h
Departs
Lands
Arrive at STL more than 15 minutes late?
Calm-weather odds: 22% · changed −2 pts in 24h
−2 pts
23%
Yes 23%
No 77%
Leave SFO more than 15 minutes late?
Calm-weather odds: 22% · changed −2 pts in 24h
−2 pts
22%
Yes 22%
No 78%
Arrive at STL more than an hour late?
Calm-weather odds: 4% · changed +0 pts in 24h
+0 pts
4%
Yes 4%
No 96%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to STL?
On time or early
77%
15–30 min late
11%
30 min–1 hour late
7%
1–2 hours late
3%
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
↑
10am departures from SFO are often late
↑
This flight has been late 34% of the time recently
↑
SFO is prone to delays
↓
Mostly benign weather forecast at SFO
↓
Saturdays in October are usually quieter than average
Weather at each end
SFO (origin)
Gusts 12 kt Ceiling none (clear) Visibility 9 mi Precip none
STL (destination)
Gusts 10 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.