Schedule: a typical Thursday (the flights of Jul 30, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 4237
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1
WN 4237 · SFO → PHX
departs 1:35 PM PT · arrives 3:45 PM MT
Forecast issued Tue 8:00 PM ET · 45h before departure
Watch this flight
Other days
Today 42%
Wed 9/30 41%
Thu 10/1
Fri 10/2 40%
Sun 10/4 28%
Mon 10/5 32%
Odds over time
Arrive at PHX more than 15 minutes late?
44%
chance · ±2 pts
+5 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
44%
Leave 15+ late
47%
Arrive 1h+ late
13%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.9d
Now
1d
12h
6h
Departs
Lands
Arrive at PHX more than 15 minutes late?
Calm-weather odds: 31% · changed +5 pts in 24h
+5 pts
44%
Yes 44%
No 56%
Leave SFO more than 15 minutes late?
Calm-weather odds: 39% · changed +0 pts in 24h
+0 pts
47%
Yes 47%
No 53%
Arrive at PHX more than an hour late?
Calm-weather odds: 7% · changed +3 pts in 24h
+3 pts
13%
Yes 13%
No 87%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 100%
How late will it get to PHX?
On time or early
56%
15–30 min late
21%
30 min–1 hour late
10%
1–2 hours late
10%
Over 2 hours late
3%
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 59% of the time recently
↑
SFO is prone to delays
↑
1pm departures from SFO are often late
↓
Mostly benign weather forecast at PHX
↓
Other factors
Weather at each end
SFO (origin)
Gusts 11 kt Ceiling 800 ft Visibility 7 mi Precip none
PHX (destination)
Gusts 5 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.