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 399 SCHEDULED · TYPICAL SCHEDULE

Thursday, October 1 Tomorrow

DL 399 · BOS → ATL

departs 4:30 PM ET · arrives 7:38 PM ET

Forecast issued Wed 2:00 AM ET · 38h before departure

Arrive at ATL more than 15 minutes late?

15% chance · ±2 pts +1 pt · 24h

HOW SURE WE ARE Moderate. The odds now blend history with early weather forecasts.

How late will it get to ATL?

On time or early
84%
15–30 min late
4%
30 min–1 hour late
6%
1–2 hours late
3%
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

↑ 4pm departures from BOS are often late

↑ Arrivals into ATL at that hour are often late

↑ Later flights pick up delays from earlier in the day

↓ Other factors

↓ Mostly benign weather forecast at ATL

Weather at each end

BOS (origin) Gusts16 kt Ceilingnone (clear) Visibility0.8 mi Precipnone

ATL (destination) Gusts13 kt Ceilingnone (clear) Visibility10+ mi Precipnone

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.

DL 399 · BOS → ATL

Odds over time

How late will it get to ATL?