Schedule: a typical Saturday (the flights of Jul 25, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
FRONTIER · FLIGHT F9 3439
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3
F9 3439 · DEN → SFO
departs 10:29 PM MT · arrives 12:23 AM PT
Forecast issued Thu 9:00 AM ET · 64h before departure
Watch this flight
Other days
Today 27%
Fri 10/2 25%
Sat 10/3
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?
24%
chance · ±5 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
24%
Leave 15+ late
31%
Arrive 1h+ late
9%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
5.1d
Now
2d
1d
12h
6h
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 21% · changed – in 24h
–
24%
Yes 24%
No 76%
Leave DEN more than 15 minutes late?
Calm-weather odds: 25% · changed – in 24h
–
31%
Yes 31%
No 69%
Arrive at SFO more than an hour late?
Calm-weather odds: 9% · changed – in 24h
–
9%
Yes 9%
No 91%
Cancelled?
Calm-weather odds: <1% · changed – in 24h
–
<1%
Yes <1%
No 99%
How late will it get to SFO?
On time or early
76%
15–30 min late
12%
30 min–1 hour late
3%
1–2 hours late
6%
Over 2 hours late
3%
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
↓
Visibility down to 2 mi forecast at SFO that day
↓
Mostly benign weather forecast at DEN
Weather at each end
DEN (origin)
Gusts 24 kt Ceiling none (clear) Visibility 10+ mi Precip none
SFO (destination)
Gusts 11 kt Ceiling none (clear) Visibility 1 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.