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 3151
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1
WN 3151 · ONT → LAS
departs 12:40 PM PT · arrives 1:45 PM PT
Forecast issued Tue 9:00 PM ET · 43h before departure
Watch this flight
Other days
Thu 10/1
Fri 10/2 24%
Mon 10/5 19%
Odds over time
Arrive at LAS more than 15 minutes late?
22%
chance · ±0 pts
+0 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
22%
Leave 15+ late
23%
Arrive 1h+ late
5%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.9d
2d
Now
1d
12h
6h
Departs
Lands
Arrive at LAS more than 15 minutes late?
Calm-weather odds: 18% · changed +0 pts in 24h
+0 pts
22%
Yes 22%
No 78%
Leave ONT more than 15 minutes late?
Calm-weather odds: 21% · changed +0 pts in 24h
+0 pts
23%
Yes 23%
No 77%
Arrive at LAS more than an hour late?
Calm-weather odds: 3% · changed +0 pts in 24h
+0 pts
5%
Yes 5%
No 95%
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
77%
15–30 min late
9%
30 min–1 hour late
9%
1–2 hours late
3%
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
↑
LAS is prone to delays
↑
Arrivals into LAS at that hour are often late
↑
Other factors
↓
Mostly benign weather forecast at LAS
↓
Thursdays in October are usually quieter than average
Weather at each end
ONT (origin)
Gusts 15 kt Ceiling 1,500 ft Visibility 4 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.