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.

DELTA · FLIGHT DL 639 SCHEDULED · TYPICAL SCHEDULE

Sunday, October 4

DL 639 · LAX → BOS

departs 6:40 AM PT · arrives 3:15 PM ET

Forecast issued Fri 8:00 PM ET · 38h before departure

Arrive at BOS more than 15 minutes late?

11% chance · ±1 pts +3 pts · 24h

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

How late will it get to BOS?

On time or early
88%
15–30 min late
3%
30 min–1 hour late
5%
1–2 hours late
<1%
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

↑ Arrivals into BOS at that hour are often late

↑ LAX is prone to delays

↓ Early flights usually leave on time

↓ 6am departures from LAX are usually not late

Weather at each end

LAX (origin) Gusts12 kt Ceilingnone (clear) Visibility10+ mi Precipnone

BOS (destination) Gusts14 kt Ceiling400 ft Visibility3 mi Precip0.02 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.

DL 639 · LAX → BOS

Odds over time

How late will it get to BOS?