Schedule: a typical Tuesday (the flights of Jul 28, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
SOUTHWEST · FLIGHT WN 4487
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Today
WN 4487 · LAS → COS
departs 8:55 PM PT · arrives 11:50 PM MT
Forecast issued Tue 9:00 PM ET · 3h before departure
Watch this flight
Other days
Today
Wed 9/30 31%
Thu 10/1 30%
Fri 10/2 38%
Mon 10/5 27%
Odds over time
Arrive at COS more than 15 minutes late?
37%
chance · ±1 pts
+14 pts · 24h
HOW SURE WE ARE
High. The odds now come mostly from live FAA and airport data.
Arrive 15+ late
37%
Leave 15+ late
42%
Arrive 1h+ late
14%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.9d
2d
1d
12h
6h
Now
Departs
Lands
Arrive at COS more than 15 minutes late?
Calm-weather odds: 36% · changed +14 pts in 24h
+14 pts
37%
Yes 37%
No 63%
Leave LAS more than 15 minutes late?
Calm-weather odds: 43% · changed +9 pts in 24h
+9 pts
42%
Yes 42%
No 58%
Arrive at COS more than an hour late?
Calm-weather odds: 14% · changed +6 pts in 24h
+6 pts
14%
Yes 14%
No 86%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to COS?
On time or early
62%
15–30 min late
11%
30 min–1 hour late
12%
1–2 hours late
11%
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
↑
8pm departures from LAS are often late
↑
WN's recent on-time record
↑
Later flights pick up delays from earlier in the day
↓
Tuesdays in September are usually quieter than average
↓
COS usually runs smoothly
Weather at each end
LAS (origin)
Gusts 27 kt Ceiling 4,700 ft Visibility 7 mi Precip 0.08 in
COS (destination)
Gusts 24 kt Ceiling 6,000 ft Visibility 10+ mi Precip 0.08 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.