Schedule: a typical Thursday (the flights of Jul 30, 2026, re-dated). Real flights replace these once the FAA publishes them, usually about a day ahead.
DELTA · FLIGHT DL 2639
SCHEDULED · TYPICAL SCHEDULE
Thursday, October 1 Today
DL 2639 · JFK → BOS
departs 9:00 PM ET · arrives 10:43 PM ET
Forecast issued Wed 11:00 PM ET · 22h before departure
Watch this flight
Other days
Today
Fri 10/2 58%
Sat 10/3 16%
Sun 10/4 36%
Mon 10/5 29%
Tue 10/6 22%
Wed 10/7 35%
Odds over time
Arrive at BOS more than 15 minutes late?
26%
chance · ±2 pts
+2 pts · 24h
HOW SURE WE ARE
Good. The odds now lean mostly on firmed-up weather forecasts.
Arrive 15+ late
26%
Leave 15+ late
30%
Arrive 1h+ late
9%
Cancelled
<1%
WEATHER FORECASTS
LIVE
IN THE AIR
0%
10%
20%
30%
40%
2.9d
2d
Now
12h
6h
Departs
Lands
Arrive at BOS more than 15 minutes late?
Calm-weather odds: 20% · changed +2 pts in 24h
+2 pts
26%
Yes 26%
No 74%
Leave JFK more than 15 minutes late?
Calm-weather odds: 28% · changed +2 pts in 24h
+2 pts
30%
Yes 30%
No 70%
Arrive at BOS more than an hour late?
Calm-weather odds: 6% · 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 BOS?
On time or early
74%
15–30 min late
8%
30 min–1 hour late
9%
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
↑
9pm departures from JFK are often late
↑
Arrivals into BOS at that hour are often late
↑
Later flights pick up delays from earlier in the day
↓
Mostly benign weather forecast at JFK
↓
Mostly benign weather forecast at BOS
Weather at each end
JFK (origin)
Gusts 11 kt Ceiling 11,000 ft Visibility 8 mi Precip none
BOS (destination)
Gusts 16 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.