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 3455
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
WN 3455 · STL → SFO
departs 5:50 PM CT · arrives 7:55 PM PT
Forecast issued Fri 10:00 PM ET · 45h before departure
Watch this flight
Odds over time
Arrive at SFO more than 15 minutes late?
32%
chance · ±8 pts
+1 pt · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
32%
Leave 15+ late
40%
Arrive 1h+ late
9%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
5.9d
Now
1d
12h
6h
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 25% · changed +1 pt in 24h
+1 pt
32%
Yes 32%
No 68%
Leave STL more than 15 minutes late?
Calm-weather odds: 38% · changed +0 pts in 24h
+0 pts
40%
Yes 40%
No 60%
Arrive at SFO more than an hour late?
Calm-weather odds: 7% · changed +1 pt in 24h
+1 pt
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 SFO?
On time or early
68%
15–30 min late
15%
30 min–1 hour late
9%
1–2 hours late
6%
Over 2 hours late
2%
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 38% of the time recently
↑
Later flights pick up delays from earlier in the day
↑
WN's recent on-time record
↓
Mostly benign weather forecast at SFO
↓
Mostly benign weather forecast at STL
Weather at each end
STL (origin)
Gusts 11 kt Ceiling none (clear) Visibility 9 mi Precip none
SFO (destination)
Gusts 12 kt Ceiling none (clear) Visibility 7 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.