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 4251
SCHEDULED · TYPICAL SCHEDULE
Saturday, October 3
F9 4251 · DEN → SLC
departs 10:13 PM MT · arrives 11:44 PM MT
Forecast issued Thu 2:00 AM ET · 70h before departure
Watch this flight
Other days
Today 41%
Fri 10/2 37%
Sat 10/3
Sun 10/4 28%
Mon 10/5 24%
Tue 10/6 16%
Wed 10/7 15%
Odds over time
Arrive at SLC more than 15 minutes late?
23%
chance · ±7 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
23%
Leave 15+ late
32%
Arrive 1h+ late
6%
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 SLC more than 15 minutes late?
Calm-weather odds: 20% · changed – in 24h
–
23%
Yes 23%
No 77%
Leave DEN more than 15 minutes late?
Calm-weather odds: 28% · changed – in 24h
–
32%
Yes 32%
No 68%
Arrive at SLC more than an hour late?
Calm-weather odds: 6% · changed – in 24h
–
6%
Yes 6%
No 94%
Cancelled?
Calm-weather odds: <1% · changed – in 24h
–
<1%
Yes <1%
No 99%
How late will it get to SLC?
On time or early
77%
15–30 min late
10%
30 min–1 hour late
7%
1–2 hours late
3%
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
↑
Later flights pick up delays from earlier in the day
↑
DEN is busy at that time
↓
Mostly benign weather forecast at SLC
↓
Mostly benign weather forecast at DEN
Weather at each end
DEN (origin)
Gusts 17 kt Ceiling none (clear) Visibility 10+ mi Precip none
SLC (destination)
Gusts 10 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.