Schedule: a typical Tuesday (the flights of Jul 28, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
REPUBLIC · FLIGHT YX 4678
SCHEDULED · TYPICAL SCHEDULE
Tuesday, September 29 Yesterday
YX 4678 · BOS → STL
departs 5:12 PM ET · arrives 7:21 PM CT
Forecast issued Tue 10:00 PM ET · 5h after departure
Watch this flight
Other days
Tue 9/29
Today 30%
Thu 10/1 35%
Fri 10/2 66%
Sat 10/3 14%
Sun 10/4 30%
Mon 10/5 28%
Tue 10/6 22%
Odds over time
Arrive at STL more than 15 minutes late?
37%
chance · ±0 pts
+10 pts · 24h
HOW SURE WE ARE
Very high. The odds now come almost entirely from live conditions.
Arrive 15+ late
37%
Leave 15+ late
32%
Arrive 1h+ late
10%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
15%
30%
45%
60%
2.8d
2d
1d
12h
6h
Departs
Lands
Arrive at STL more than 15 minutes late?
Calm-weather odds: 37% · changed +10 pts in 24h
+10 pts
37%
Yes 37%
No 63%
Leave BOS more than 15 minutes late?
Calm-weather odds: 32% · changed +4 pts in 24h
+4 pts
32%
Yes 32%
No 68%
Arrive at STL more than an hour late?
Calm-weather odds: 10% · changed +3 pts in 24h
+3 pts
10%
Yes 10%
No 90%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to STL?
On time or early
63%
15–30 min late
16%
30 min–1 hour late
10%
1–2 hours late
8%
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
↑
5pm departures from BOS are often late
↑
BOS is prone to delays
↑
Cloud base down to 600 ft, visibility down to 1.5 mi forecast at BOS that day
↓
Mostly benign weather forecast at STL
↓
Tuesdays in September are usually quieter than average
Weather at each end
BOS (origin)
Gusts 11 kt Ceiling 600 ft Visibility 1.5 mi Precip 0.03 in
STL (destination)
Gusts 9 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.