Schedule: a typical summer Saturday (the flights of Jul 25, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SOUTHWEST · FLIGHT WN 4577
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3 Today
WN 4577 · BWI → BUF
departs 9:55 PM ET · arrives 11:15 PM ET
Forecast issued Sat 12:00 AM ET · 22h before departure
Watch this flight
Other days
Today
Mon 10/5 21%
Fri 10/9 24%
Odds over time
Arrive at BUF more than 15 minutes late?
30%
chance · ±4 pts
+12 pts · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
30%
Leave 15+ late
31%
Arrive 1h+ late
9%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
5.0d
2d
Now
12h
6h
Departs
Lands
Arrive at BUF more than 15 minutes late?
Calm-weather odds: 25% · changed +12 pts in 24h
+12 pts
30%
Yes 30%
No 70%
Leave BWI more than 15 minutes late?
Calm-weather odds: 30% · changed +2 pts in 24h
+2 pts
31%
Yes 31%
No 69%
Arrive at BUF more than an hour late?
Calm-weather odds: 8% · changed +3 pts in 24h
+3 pts
9%
Yes 9%
No 91%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to BUF?
On time or early
70%
15–30 min late
16%
30 min–1 hour late
5%
1–2 hours late
8%
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
↑
9pm departures from BWI are often late
↑
Later flights pick up delays from earlier in the day
↑
WN's recent on-time record
↓
Mostly benign weather forecast at BWI
↓
Saturdays in October are usually quieter than average
Weather at each end
BWI (origin)
Gusts 14 kt Ceiling 2,700 ft Visibility 10+ mi Precip none
BUF (destination)
Gusts 11 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.