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 3840
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3 Yesterday
WN 3840 · SJU → AUS
departs 3:15 PM AT · arrives 7:05 PM CT
Forecast issued Sat 10:00 PM ET · 7h after departure
Watch this flight
Odds over time
Arrive at AUS more than 15 minutes late?
39%
chance · ±0 pts
+6 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
39%
Leave 15+ late
40%
Arrive 1h+ late
9%
Cancelled
1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
20%
40%
60%
80%
4.7d
2d
1d
12h
6h
Departs
Lands
Arrive at AUS more than 15 minutes late?
Calm-weather odds: 40% · changed +6 pts in 24h
+6 pts
39%
Yes 39%
No 61%
Leave SJU more than 15 minutes late?
Calm-weather odds: 38% · changed +7 pts in 24h
+7 pts
40%
Yes 40%
No 60%
Arrive at AUS more than an hour late?
Calm-weather odds: 8% · changed +2 pts in 24h
+2 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 AUS?
On time or early
60%
15–30 min late
21%
30 min–1 hour late
8%
1–2 hours late
7%
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
↑
Cloud base down to 800 ft forecast at AUS that day
↑
Arrivals into AUS at that hour are often late
↑
3pm departures from SJU are often late
↓
Saturdays in October are usually quieter than average
↓
SJU usually runs smoothly
Weather at each end
SJU (origin)
Gusts 25 kt Ceiling 8,500 ft Visibility 10+ mi Precip none
AUS (destination)
Gusts 20 kt Ceiling 800 ft Visibility 6 mi Precip 0.02 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.