Schedule: a typical Wednesday (the flights of Jul 29, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
FRONTIER · FLIGHT F9 4278
SCHEDULED · TYPICAL SCHEDULE
Wednesday, September 30 Today
F9 4278 · LAS → IAD
departs 12:46 AM PT · arrives 8:20 AM ET
Forecast issued Wed 7:00 PM ET · 15h after departure
Watch this flight
Other days
Today
Thu 10/1 26%
Fri 10/2 24%
Sat 10/3 22%
Sun 10/4 25%
Mon 10/5 27%
Tue 10/6 19%
Odds over time
Arrive at IAD more than 15 minutes late?
24%
chance · ±0 pts
−2 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
24%
Leave 15+ late
34%
Arrive 1h+ late
9%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.7d
2d
1d
12h
6h
Departs
Lands
Arrive at IAD more than 15 minutes late?
Calm-weather odds: 24% · changed −2 pts in 24h
−2 pts
24%
Yes 24%
No 76%
Leave LAS more than 15 minutes late?
Calm-weather odds: 34% · changed −1 pt in 24h
−1 pt
34%
Yes 34%
No 66%
Arrive at IAD more than an hour late?
Calm-weather odds: 9% · changed +0 pts in 24h
+0 pts
9%
Yes 9%
No 91%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to IAD?
On time or early
75%
15–30 min late
3%
30 min–1 hour late
12%
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 26% of the time recently
↑
LAS is prone to delays
↓
Wednesdays in September are usually quieter than average
↓
Mostly benign weather forecast at IAD
Weather at each end
LAS (origin)
Gusts 18 kt Ceiling none (clear) Visibility 10+ mi Precip none
IAD (destination)
Gusts 8 kt Ceiling 5,000 ft Visibility 6 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.