Schedule: a typical summer Friday (the flights of Jul 31, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
FRONTIER · FLIGHT F9 4251
SCHEDULED · TYPICAL SCHEDULE
Friday, October 2 Today
F9 4251 · DEN → SLC
departs 10:13 PM MT · arrives 11:44 PM MT
Forecast issued Fri 3:00 AM ET · 21h before departure
Watch this flight
Other days
Today
Sat 10/3 28%
Sun 10/4 36%
Mon 10/5 24%
Tue 10/6 16%
Wed 10/7 15%
Odds over time
Arrive at SLC more than 15 minutes late?
37%
chance · ±11 pts
+1 pt · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
37%
Leave 15+ late
42%
Arrive 1h+ late
8%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
4.1d
2d
Now
12h
6h
Departs
Lands
Arrive at SLC more than 15 minutes late?
Calm-weather odds: 26% · changed +1 pt in 24h
+1 pt
37%
Yes 37%
No 63%
Leave DEN more than 15 minutes late?
Calm-weather odds: 32% · changed +2 pts in 24h
+2 pts
42%
Yes 42%
No 58%
Arrive at SLC more than an hour late?
Calm-weather odds: 7% · changed +0 pts in 24h
+0 pts
8%
Yes 8%
No 92%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to SLC?
On time or early
62%
15–30 min late
18%
30 min–1 hour late
11%
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
↑
Later flights pick up delays from earlier in the day
↑
10pm departures from DEN are often late
↓
Mostly benign weather forecast at SLC
↓
Gusts to 28 kt forecast at DEN that day
Weather at each end
DEN (origin)
Gusts 29 kt Ceiling none (clear) Visibility 10+ mi Precip none
SLC (destination)
Gusts 12 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.