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 4177
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Today
WN 4177 · LAS → SMF
departs 3:15 PM PT · arrives 4:50 PM PT
Forecast issued Tue 3:00 PM ET · 3h before departure
Watch this flight
Other days
Today
Wed 9/30 22%
Sat 10/3 20%
Odds over time
Arrive at SMF more than 15 minutes late?
71%
chance · ±2 pts
+28 pts · 24h
HOW SURE WE ARE
High. The odds now come mostly from live FAA and airport data.
Arrive 15+ late
71%
Leave 15+ late
65%
Arrive 1h+ late
25%
Cancelled
2%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
25%
50%
75%
100%
2.9d
2d
1d
12h
6h
Now
Departs
Lands
Arrive at SMF more than 15 minutes late?
Calm-weather odds: 64% · changed +28 pts in 24h
+28 pts
71%
Yes 71%
No 29%
Leave LAS more than 15 minutes late?
Calm-weather odds: 62% · changed +15 pts in 24h
+15 pts
65%
Yes 65%
No 35%
Arrive at SMF more than an hour late?
Calm-weather odds: 19% · changed +18 pts in 24h
+18 pts
25%
Yes 25%
No 75%
Cancelled?
Calm-weather odds: 2% · changed +1 pt in 24h
+1 pt
2%
Yes 2%
No 98%
How late will it get to SMF?
On time or early
29%
15–30 min late
21%
30 min–1 hour late
24%
1–2 hours late
20%
Over 2 hours late
4%
Cancelled
2%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
Mostly benign weather forecast at LAS
↑
LAS is prone to delays
↑
3pm departures from LAS are often late
↓
Tuesdays in September are usually quieter than average
↓
Mostly benign weather forecast at SMF
Weather at each end
LAS (origin)
Gusts 23 kt Ceiling 4,700 ft Visibility 7 mi Precip 0.19 in
SMF (destination)
Gusts 16 kt Ceiling none (clear) Visibility 9 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.