Schedule: a typical Saturday (the flights of Jul 25, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 3153
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3
WN 3153 · ONT → MDW
departs 11:55 PM PT · arrives 5:40 AM CT
Forecast issued Thu 7:00 PM ET · 56h before departure
Watch this flight
Other days
Today 20%
Fri 10/2 16%
Sat 10/3
Sun 10/4 15%
Mon 10/5 12%
Tue 10/6 12%
Wed 10/7 11%
Odds over time
Arrive at MDW more than 15 minutes late?
10%
chance · ±1 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
10%
Leave 15+ late
14%
Arrive 1h+ late
3%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
5%
10%
15%
20%
5.2d
Now
2d
1d
12h
6h
Departs
Lands
Arrive at MDW more than 15 minutes late?
Calm-weather odds: 8% · changed – in 24h
–
10%
Yes 10%
No 90%
Leave ONT more than 15 minutes late?
Calm-weather odds: 11% · changed – in 24h
–
14%
Yes 14%
No 86%
Arrive at MDW more than an hour late?
Calm-weather odds: 2% · changed – in 24h
–
3%
Yes 3%
No 97%
Cancelled?
Calm-weather odds: <1% · changed – in 24h
–
<1%
Yes <1%
No 99%
How late will it get to MDW?
On time or early
89%
15–30 min late
4%
30 min–1 hour late
3%
1–2 hours late
2%
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
↑
Other factors
↓
Saturdays in October are usually quieter than average
↓
Mostly benign weather forecast at MDW
Weather at each end
ONT (origin)
Gusts 14 kt Ceiling none (clear) Visibility 10+ mi Precip none
MDW (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.