Schedule: a typical Wednesday (the flights of Jul 29, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 21
SCHEDULED · TYPICAL SCHEDULE
Wednesday, September 30 Tomorrow
WN 21 · PHX → SMF
departs 11:30 AM MT · arrives 1:25 PM PT
Forecast issued Tue 9:00 PM ET · 18h before departure
Watch this flight
Other days
Today 37%
Wed 9/30
Odds over time
Arrive at SMF more than 15 minutes late?
24%
chance · ±4 pts
+9 pts · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
24%
Leave 15+ late
26%
Arrive 1h+ late
3%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.9d
2d
1d
Now
12h
6h
Departs
Lands
Arrive at SMF more than 15 minutes late?
Calm-weather odds: 24% · changed +9 pts in 24h
+9 pts
24%
Yes 24%
No 76%
Leave PHX more than 15 minutes late?
Calm-weather odds: 22% · changed +4 pts in 24h
+4 pts
26%
Yes 26%
No 74%
Arrive at SMF more than an hour late?
Calm-weather odds: 3% · changed +1 pt in 24h
+1 pt
3%
Yes 3%
No 97%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to SMF?
On time or early
75%
15–30 min late
11%
30 min–1 hour late
10%
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
↑
11am departures from PHX are often late
↑
PHX is busy at that time
↑
SMF is prone to delays
↓
Mostly benign weather forecast at SMF
↓
Wednesdays in September are usually quieter than average
Weather at each end
PHX (origin)
Gusts 8 kt Ceiling none (clear) Visibility 10+ mi Precip 0.03 in
SMF (destination)
Gusts 6 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.