Schedule: a typical summer Tuesday (the flights of Jul 28, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SOUTHWEST · FLIGHT WN 4120
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29
WN 4120 · RSW → MDW
departs 6:25 PM ET · arrives 8:15 PM CT
Forecast issued Tue 10:00 PM ET · 4h after departure
Watch this flight
Other days
Tue 9/29
Mon 10/5 22%
Fri 10/9 28%
Odds over time
Arrive at MDW more than 15 minutes late?
30%
chance · ±0 pts
−11 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
30%
Leave 15+ late
31%
Arrive 1h+ late
4%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
1d
12h
6h
Departs
Lands
Arrive at MDW more than 15 minutes late?
Calm-weather odds: 28% · changed −11 pts in 24h
−11 pts
30%
Yes 30%
No 70%
Leave RSW more than 15 minutes late?
Calm-weather odds: 31% · changed −6 pts in 24h
−6 pts
31%
Yes 31%
No 69%
Arrive at MDW more than an hour late?
Calm-weather odds: 4% · changed −8 pts in 24h
−8 pts
4%
Yes 4%
No 96%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to MDW?
On time or early
70%
15–30 min late
10%
30 min–1 hour late
16%
1–2 hours late
2%
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
↑
Arrivals into MDW at that hour are often late
↑
Later flights pick up delays from earlier in the day
↑
This flight has been late 40% of the time recently
↓
Tuesdays in September are usually quieter than average
↓
Mostly benign weather forecast at MDW
Weather at each end
RSW (origin)
Gusts 9 kt Ceiling 3,400 ft Visibility 7 mi Precip 0.12 in
MDW (destination)
Gusts 15 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.