Schedule: a typical summer Sunday (the flights of Jul 26, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
SOUTHWEST · FLIGHT WN 4539
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
WN 4539 · BOI → OAK
departs 3:40 PM MT · arrives 4:25 PM PT
Forecast issued Fri 5:00 PM ET · 49h before departure
Watch this flight
Other days
Today 22%
Sat 10/3 8%
Sun 10/4
Mon 10/5 17%
Odds over time
Arrive at OAK more than 15 minutes late?
20%
chance · ±1 pts
−2 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
20%
Leave 15+ late
23%
Arrive 1h+ late
6%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
5.8d
Now
1d
12h
6h
Departs
Lands
Arrive at OAK more than 15 minutes late?
Calm-weather odds: 18% · changed −2 pts in 24h
−2 pts
20%
Yes 20%
No 80%
Leave BOI more than 15 minutes late?
Calm-weather odds: 20% · changed +1 pt in 24h
+1 pt
23%
Yes 23%
No 77%
Arrive at OAK more than an hour late?
Calm-weather odds: 5% · changed +0 pts in 24h
+0 pts
6%
Yes 6%
No 94%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 100%
How late will it get to OAK?
On time or early
79%
15–30 min late
9%
30 min–1 hour late
5%
1–2 hours late
5%
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
↑
This flight has been late 35% of the time recently
↑
Arrivals into OAK at that hour are often late
↑
WN's recent on-time record
↓
Mostly benign weather forecast at OAK
↓
Sundays in October are usually quieter than average
Weather at each end
BOI (origin)
Gusts 10 kt Ceiling none (clear) Visibility 10+ mi Precip none
OAK (destination)
Gusts 11 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.