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 4120
SCHEDULED · TYPICAL SCHEDULE
Wednesday, September 30 Yesterday
WN 4120 · RSW → MDW
departs 6:25 PM ET · arrives 8:15 PM CT
Forecast issued Wed 10:00 PM ET · 4h after departure
Watch this flight
Other days
Wed 9/30
Today 64%
Fri 10/2 39%
Sat 10/3 7%
Mon 10/5 20%
Tue 10/6 35%
Wed 10/7 26%
Odds over time
Arrive at MDW more than 15 minutes late?
50%
chance · ±0 pts
−6 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
50%
Leave 15+ late
45%
Arrive 1h+ late
12%
Cancelled
1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
20%
40%
60%
80%
2.8d
2d
1d
12h
6h
Departs
Lands
Arrive at MDW more than 15 minutes late?
Calm-weather odds: 50% · changed −6 pts in 24h
−6 pts
50%
Yes 50%
No 50%
Leave RSW more than 15 minutes late?
Calm-weather odds: 45% · changed −6 pts in 24h
−6 pts
45%
Yes 45%
No 55%
Arrive at MDW more than an hour late?
Calm-weather odds: 11% · changed −1 pt in 24h
−1 pt
12%
Yes 12%
No 88%
Cancelled?
Calm-weather odds: 1% · changed −1 pt in 24h
−1 pt
1%
Yes 1%
No 99%
How late will it get to MDW?
On time or early
50%
15–30 min late
22%
30 min–1 hour late
16%
1–2 hours late
9%
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
↑
Cloud base down to 800 ft, visibility down to 2.5 mi, 0.8 in of rain forecast at MDW that day
↑
Arrivals into MDW at that hour are often late
↑
Thunderstorms forecast at RSW that day
↓
Wednesdays in September are usually quieter than average
↓
RSW usually runs smoothly
Weather at each end
RSW (origin)
Gusts 12 kt Ceiling 5,000 ft Visibility 10+ mi Precip 0.01 in
MDW (destination)
Gusts 21 kt Ceiling 700 ft Visibility 2.5 mi Precip 0.94 in
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.