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 3644
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1 Tomorrow
WN 3644 · SFO → LAS
departs 1:20 PM PT · arrives 3:00 PM PT
Forecast issued Wed 2:00 AM ET · 38h before departure
Watch this flight
Other days
Today 37%
Thu 10/1
Fri 10/2 31%
Mon 10/5 26%
Tue 10/6 19%
Odds over time
Arrive at LAS more than 15 minutes late?
41%
chance · ±4 pts
+4 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
41%
Leave 15+ late
52%
Arrive 1h+ late
13%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
Now
1d
12h
6h
Departs
Lands
Arrive at LAS more than 15 minutes late?
Calm-weather odds: 26% · changed +4 pts in 24h
+4 pts
41%
Yes 41%
No 59%
Leave SFO more than 15 minutes late?
Calm-weather odds: 42% · changed +3 pts in 24h
+3 pts
52%
Yes 52%
No 48%
Arrive at LAS more than an hour late?
Calm-weather odds: 8% · 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 99%
How late will it get to LAS?
On time or early
59%
15–30 min late
14%
30 min–1 hour late
14%
1–2 hours late
9%
Over 2 hours late
4%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
1pm departures from SFO are often late
↑
SFO is prone to delays
↑
This flight has been late 58% of the time recently
↓
Mostly benign weather forecast at LAS
↓
Other factors
Weather at each end
SFO (origin)
Gusts 11 kt Ceiling 800 ft Visibility 7 mi Precip none
LAS (destination)
Gusts 9 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.