Schedule: a typical Thursday (the flights of Jul 30, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 1539
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1 Tomorrow
WN 1539 · DEN → GRR
departs 1:00 PM MT · arrives 5:20 PM ET
Forecast issued Wed 9:00 AM ET · 30h before departure
Watch this flight
Other days
Today 46%
Thu 10/1
Fri 10/2 27%
Sun 10/4 19%
Mon 10/5 23%
Tue 10/6 20%
Odds over time
Arrive at GRR more than 15 minutes late?
37%
chance · ±5 pts
−4 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
37%
Leave 15+ late
30%
Arrive 1h+ late
8%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
Now
1d
12h
6h
Departs
Lands
Arrive at GRR more than 15 minutes late?
Calm-weather odds: 22% · changed −4 pts in 24h
−4 pts
37%
Yes 37%
No 63%
Leave DEN more than 15 minutes late?
Calm-weather odds: 27% · changed −9 pts in 24h
−9 pts
30%
Yes 30%
No 70%
Arrive at GRR more than an hour late?
Calm-weather odds: 3% · changed −1 pt in 24h
−1 pt
8%
Yes 8%
No 92%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to GRR?
On time or early
63%
15–30 min late
21%
30 min–1 hour late
7%
1–2 hours late
7%
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
↑
Cloud base down to 300 ft, visibility down to 2 mi, 0.9 in of rain forecast at GRR that day
↑
Other factors
↑
This flight has been late 37% of the time recently
↓
GRR usually runs smoothly
↓
Mostly benign weather forecast at DEN
Weather at each end
DEN (origin)
Gusts 21 kt Ceiling 7,000 ft Visibility 10+ mi Precip none
GRR (destination)
Gusts 19 kt Ceiling 300 ft Visibility 2 mi Precip 0.86 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.