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 3155
SCHEDULED · TYPICAL SCHEDULE
Wednesday, September 30 Today
WN 3155 · ONT → OAK
departs 4:05 PM PT · arrives 5:25 PM PT
Forecast issued Wed 2:00 AM ET · 17h before departure
Watch this flight
Other days
Today
Thu 10/1 23%
Fri 10/2 23%
Sat 10/3 9%
Sun 10/4 20%
Mon 10/5 16%
Tue 10/6 10%
Odds over time
Arrive at OAK more than 15 minutes late?
12%
chance · ±1 pts
+1 pt · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
12%
Leave 15+ late
22%
Arrive 1h+ late
5%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
5%
10%
15%
20%
2.8d
2d
1d
Now
12h
6h
Departs
Lands
Arrive at OAK more than 15 minutes late?
Calm-weather odds: 10% · changed +1 pt in 24h
+1 pt
12%
Yes 12%
No 88%
Leave ONT more than 15 minutes late?
Calm-weather odds: 20% · changed +0 pts in 24h
+0 pts
22%
Yes 22%
No 78%
Arrive at OAK more than an hour late?
Calm-weather odds: 4% · 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 OAK?
On time or early
88%
15–30 min late
5%
30 min–1 hour late
2%
1–2 hours late
4%
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
↑
Later flights pick up delays from earlier in the day
↑
WN's recent on-time record
↑
Arrivals into OAK at that hour are often late
↓
Wednesdays in September are usually quieter than average
↓
Cloud base down to 1,300 ft forecast at OAK that day
Weather at each end
ONT (origin)
Gusts 17 kt Ceiling none (clear) Visibility 8 mi Precip none
OAK (destination)
Gusts 11 kt Ceiling 1,300 ft Visibility 7 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.