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.
ALLEGIANT · FLIGHT G4 571
SCHEDULED · TYPICAL SCHEDULE
Sunday, October 4
G4 571 · BOS → GRR
departs 9:18 AM ET · arrives 11:31 AM ET
Forecast issued Fri 10:00 AM ET · 47h before departure
Watch this flight
Odds over time
Arrive at GRR more than 15 minutes late?
8%
chance · ±0 pts
+0 pts · 24h
HOW SURE WE ARE
Moderate. The odds now blend history with early weather forecasts.
Arrive 15+ late
8%
Leave 15+ late
10%
Arrive 1h+ late
3%
Cancelled
<1%
MOSTLY HISTORY
WEATHER FORECASTS
LIVE
IN THE AIR
0%
5%
10%
15%
20%
5.5d
Now
1d
12h
6h
Departs
Lands
Arrive at GRR more than 15 minutes late?
Calm-weather odds: 9% · changed +0 pts in 24h
+0 pts
8%
Yes 8%
No 92%
Leave BOS more than 15 minutes late?
Calm-weather odds: 10% · changed +0 pts in 24h
+0 pts
10%
Yes 10%
No 90%
Arrive at GRR more than an hour late?
Calm-weather odds: 3% · changed +0 pts in 24h
+0 pts
3%
Yes 3%
No 97%
Cancelled?
Calm-weather odds: <1% · changed +0 pts in 24h
+0 pts
<1%
Yes <1%
No 99%
How late will it get to GRR?
On time or early
91%
15–30 min late
2%
30 min–1 hour late
3%
1–2 hours late
2%
Over 2 hours late
1%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.
What’s moving the odds
↑
G4's recent on-time record
↑
Other factors
↓
Cloud base down to 1,000 ft forecast at BOS that day
↓
GRR usually runs smoothly
Weather at each end
BOS (origin)
Gusts 14 kt Ceiling 1,700 ft Visibility 10+ mi Precip none
GRR (destination)
Gusts 21 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.