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 1539
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3
WN 1539 · GRR → MDW
departs 4:40 PM ET · arrives 4:45 PM CT
Forecast issued Thu 5:00 PM ET · 48h before departure
Watch this flight
Other days
Today 48%
Fri 10/2 27%
Sat 10/3
Sun 10/4 19%
Mon 10/5 21%
Odds over time
Arrive at MDW more than 15 minutes late?
12%
chance · ±2 pts
+0 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
12%
Leave 15+ late
19%
Arrive 1h+ late
4%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
5%
10%
15%
20%
4.8d
Now
1d
12h
6h
Departs
Lands
Arrive at MDW more than 15 minutes late?
Calm-weather odds: 11% · changed +0 pts in 24h
+0 pts
12%
Yes 12%
No 88%
Leave GRR more than 15 minutes late?
Calm-weather odds: 17% · changed +1 pt in 24h
+1 pt
19%
Yes 19%
No 81%
Arrive at MDW more than an hour late?
Calm-weather odds: 3% · changed +0 pts in 24h
+0 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
88%
15–30 min late
4%
30 min–1 hour late
5%
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
↑
This flight has been late 45% of the time recently
↑
Later flights pick up delays from earlier in the day
↑
Arrivals into MDW at that hour are often late
↓
Mostly benign weather forecast at MDW
↓
GRR usually runs smoothly
Weather at each end
GRR (origin)
Gusts 12 kt Ceiling none (clear) Visibility 8 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.