Schedule: a typical Thursday (the flights of Jul 30, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
FRONTIER · FLIGHT F9 3439
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1 Today
F9 3439 · DEN → SFO
departs 10:29 PM MT · arrives 12:23 AM PT
Forecast issued Thu 3:00 AM ET · 22h before departure
Watch this flight
Other days
Today
Fri 10/2 26%
Sun 10/4 24%
Mon 10/5 22%
Tue 10/6 15%
Wed 10/7 16%
Odds over time
Arrive at SFO more than 15 minutes late?
28%
chance · ±5 pts
+2 pts · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
28%
Leave 15+ late
42%
Arrive 1h+ late
11%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
Now
12h
6h
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 25% · changed +2 pts in 24h
+2 pts
28%
Yes 28%
No 72%
Leave DEN more than 15 minutes late?
Calm-weather odds: 35% · changed +10 pts in 24h
+10 pts
42%
Yes 42%
No 58%
Arrive at SFO more than an hour late?
Calm-weather odds: 10% · changed +0 pts in 24h
+0 pts
11%
Yes 11%
No 89%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to SFO?
On time or early
71%
15–30 min late
4%
30 min–1 hour late
13%
1–2 hours late
6%
Over 2 hours late
4%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
F9's recent on-time record
↑
This flight has been late 29% of the time recently
↑
Later flights pick up delays from earlier in the day
↓
Cloud base down to 300 ft forecast at SFO that day
↓
Thursdays in October are usually quieter than average
Weather at each end
DEN (origin)
Gusts 23 kt Ceiling none (clear) Visibility 10+ mi Precip none
SFO (destination)
Gusts 11 kt Ceiling 200 ft Visibility 3 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.