Schedule: a typical Tuesday (the flights of Jul 28, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3155
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Today
WN 3155 · LAS → ONT
departs 2:25 PM PT · arrives 3:30 PM PT
Forecast issued Tue 4:00 PM ET · 1h before departure
Watch this flight
Other days
Today
Wed 9/30 33%
Odds over time
Arrive at ONT more than 15 minutes late?
56%
chance · ±3 pts
+15 pts · 24h
HOW SURE WE ARE
High. The odds now come mostly from live FAA and airport data.
Arrive 15+ late
56%
Leave 15+ late
50%
Arrive 1h+ late
10%
Cancelled
1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
25%
50%
75%
100%
2.9d
2d
1d
12h
6h
Now
Departs
Lands
Arrive at ONT more than 15 minutes late?
Calm-weather odds: 51% · changed +15 pts in 24h
+15 pts
56%
Yes 56%
No 44%
Leave LAS more than 15 minutes late?
Calm-weather odds: 52% · changed +2 pts in 24h
+2 pts
50%
Yes 50%
No 50%
Arrive at ONT more than an hour late?
Calm-weather odds: 10% · changed +1 pt in 24h
+1 pt
10%
Yes 10%
No 90%
Cancelled?
Calm-weather odds: 1% · changed +1 pt in 24h
+1 pt
1%
Yes 1%
No 99%
How late will it get to ONT?
On time or early
44%
15–30 min late
23%
30 min–1 hour late
23%
1–2 hours late
7%
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
↑
LAS is prone to delays
↑
2pm departures from LAS are often late
↑
Mostly benign weather forecast at LAS
↓
Tuesdays in September are usually quieter than average
↓
Mostly benign weather forecast at ONT
Weather at each end
LAS (origin)
Gusts 23 kt Ceiling 4,700 ft Visibility 7 mi Precip 0.07 in
ONT (destination)
Gusts 20 kt Ceiling none (clear) Visibility 9 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.