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.
FRONTIER · FLIGHT F9 2421
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
F9 2421 · DEN → SAN
departs 7:40 AM MT · arrives 9:05 AM PT
Forecast issued Fri 7:00 AM ET · 51h before departure
Watch this flight
Other days
Today 26%
Sat 10/3 28%
Sun 10/4
Mon 10/5 23%
Tue 10/6 20%
Wed 10/7 20%
Odds over time
Arrive at SAN more than 15 minutes late?
22%
chance · ±1 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
22%
Leave 15+ late
16%
Arrive 1h+ late
5%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
5.5d
Now
1d
12h
6h
Departs
Lands
Arrive at SAN more than 15 minutes late?
Calm-weather odds: 24% · changed – in 24h
–
22%
Yes 22%
No 78%
Leave DEN more than 15 minutes late?
Calm-weather odds: 15% · changed – in 24h
–
16%
Yes 16%
No 84%
Arrive at SAN more than an hour late?
Calm-weather odds: 6% · changed – in 24h
–
5%
Yes 5%
No 95%
Cancelled?
Calm-weather odds: <1% · changed – in 24h
–
<1%
Yes <1%
No 99%
How late will it get to SAN?
On time or early
77%
15–30 min late
11%
30 min–1 hour late
5%
1–2 hours late
4%
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
↑
F9's recent on-time record
↑
SAN is prone to delays
↑
Sundays in October are usually busier than average
↓
Gusts to 27 kt forecast at DEN that day
↓
Early flights usually leave on time
Weather at each end
DEN (origin)
Gusts 27 kt Ceiling none (clear) Visibility 10+ mi Precip none
SAN (destination)
Gusts 13 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.