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.
REPUBLIC · FLIGHT YX 4509
SCHEDULED · TYPICAL SCHEDULE
Friday, October 2
YX 4509 · LGA → STL
departs 12:58 PM ET · arrives 2:50 PM CT
Forecast issued Fri 10:00 PM ET · 9h after departure
Watch this flight
Other days
Fri 10/2
Today 18%
Mon 10/5 10%
Fri 10/9 13%
Odds over time
Arrive at STL more than 15 minutes late?
15%
chance · ±0 pts
−5 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
15%
Leave 15+ late
14%
Arrive 1h+ late
5%
Cancelled
2%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
3.6d
2d
1d
12h
6h
Departs
Lands
Arrive at STL more than 15 minutes late?
Calm-weather odds: 15% · changed −5 pts in 24h
−5 pts
15%
Yes 15%
No 85%
Leave LGA more than 15 minutes late?
Calm-weather odds: 14% · changed −5 pts in 24h
−5 pts
14%
Yes 14%
No 86%
Arrive at STL more than an hour late?
Calm-weather odds: 5% · changed −1 pt in 24h
−1 pt
5%
Yes 5%
No 95%
Cancelled?
Calm-weather odds: 2% · changed +0 pts in 24h
+0 pts
2%
Yes 2%
No 98%
How late will it get to STL?
On time or early
83%
15–30 min late
6%
30 min–1 hour late
4%
1–2 hours late
3%
Over 2 hours late
2%
Cancelled
2%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
0.3 in of rain forecast at LGA that day
↑
LGA is prone to delays
↑
Cloud base down to 600 ft forecast at STL that day
↓
LGA is quiet at that time
↓
Other factors
Weather at each end
LGA (origin)
Gusts 25 kt Ceiling 4,900 ft Visibility 10+ mi Precip 0.01 in
STL (destination)
Gusts 20 kt Ceiling 600 ft Visibility 9 mi Precip 0.01 in
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.