UA 1866 · IAD → BOS

departs 10:25 PM ET · arrives 12:24 AM ET

Forecast issued Mon 3:00 AM ET · 19h before departure

Arrive at BOS more than 15 minutes late?

15% chance · ±1 pts – · 24h

HOW SURE WE ARE Good. The odds now lean mostly on firmed-up weather forecasts.

How late will it get to BOS?

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

↑ UA's recent on-time record

↑ 10pm departures from IAD are often late

↑ Arrivals into BOS at that hour are often late

↓ Mondays in October are usually quieter than average

↓ Cloud base down to 300 ft forecast at IAD that day

Weather at each end

IAD (origin) Gusts20 kt Ceiling3,000 ft Visibility4 mi Precipnone

BOS (destination) Gusts26 kt Ceiling900 ft Visibility6 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.

UA 1866 · IAD → BOS

Odds over time

How late will it get to BOS?