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 4377
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Yesterday
WN 4377 · DCA → DAL
departs 8:35 PM ET · arrives 10:55 PM CT
Forecast issued Tue 10:00 PM ET · 1h after departure
Watch this flight
Other days
Tue 9/29
Today 54%
Thu 10/1 56%
Fri 10/2 39%
Sun 10/4 38%
Mon 10/5 30%
Tue 10/6 24%
Odds over time
Arrive at DAL more than 15 minutes late?
30%
chance · ±0 pts
+1 pt · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
30%
Leave 15+ late
38%
Arrive 1h+ late
8%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.8d
2d
1d
12h
6h
Departs
Now
Lands
Arrive at DAL more than 15 minutes late?
Calm-weather odds: 28% · changed +1 pt in 24h
+1 pt
30%
Yes 30%
No 70%
Leave DCA more than 15 minutes late?
Calm-weather odds: 39% · changed +0 pts in 24h
+0 pts
38%
Yes 38%
No 62%
Arrive at DAL more than an hour late?
Calm-weather odds: 8% · changed +0 pts in 24h
+0 pts
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 DAL?
On time or early
70%
15–30 min late
11%
30 min–1 hour late
11%
1–2 hours late
6%
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
↑
8pm departures from DCA are often late
↑
This flight has been late 43% of the time recently
↑
Later flights pick up delays from earlier in the day
↓
Mostly benign weather forecast at DCA
↓
Tuesdays in September are usually quieter than average
Weather at each end
DCA (origin)
Gusts 7 kt Ceiling 4,000 ft Visibility 9.6 mi Precip none
DAL (destination)
Gusts 20 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.