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 3999
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
F9 3999 · DFW → SFO
departs 8:59 PM CT · arrives 10:59 PM PT
Forecast issued Fri 5:00 AM ET · 65h before departure
Watch this flight
Other days
Today 46%
Sat 10/3 41%
Sun 10/4
Mon 10/5 36%
Tue 10/6 25%
Wed 10/7 31%
Odds over time
Arrive at SFO more than 15 minutes late?
41%
chance · ±5 pts
– · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
41%
Leave 15+ late
45%
Arrive 1h+ late
16%
Cancelled
2%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
6.0d
Now
2d
1d
12h
6h
Departs
Lands
Arrive at SFO more than 15 minutes late?
Calm-weather odds: 37% · changed – in 24h
–
41%
Yes 41%
No 59%
Leave DFW more than 15 minutes late?
Calm-weather odds: 38% · changed – in 24h
–
45%
Yes 45%
No 55%
Arrive at SFO more than an hour late?
Calm-weather odds: 13% · changed – in 24h
–
16%
Yes 16%
No 84%
Cancelled?
Calm-weather odds: 1% · changed – in 24h
–
2%
Yes 2%
No 98%
How late will it get to SFO?
On time or early
58%
15–30 min late
8%
30 min–1 hour late
17%
1–2 hours late
11%
Over 2 hours late
5%
Cancelled
2%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
This flight has been late 42% of the time recently
↑
8pm departures from DFW are often late
↑
Later flights pick up delays from earlier in the day
↓
Mostly benign weather forecast at SFO
↓
Sundays in October are usually quieter than average
Weather at each end
DFW (origin)
Gusts 19 kt Ceiling 700 ft Visibility 4 mi Precip 0.05 in
SFO (destination)
Gusts 12 kt Ceiling none (clear) Visibility 8 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.