UA 939 · LHR → SFO

departs 4:29 PM BST · arrives 7:35 PM PT

Forecast issued Thu 10:00 PM ET · 10h after departure

Arrive at SFO more than 15 minutes late?

23% chance · ±0 pts +4 pts · 24h

HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.

How late will it get to SFO?

On time or early
74%
15–30 min late
<1%
30 min–1 hour late
11%
1–2 hours late
3%
Over 2 hours late
8%
Cancelled
4%

Gate arrival compared with the scheduled arrival. The ranges add up to 100%.

What’s moving the odds

↑ Arrivals into SFO at that hour are often late

↑ Later flights pick up delays from earlier in the day

↑ SFO is prone to delays

↓ Other factors

↓ Cloud base down to 200 ft forecast at SFO that day

Weather at each end

LHR (origin) Gusts— Ceiling— Visibility— Precip—

SFO (destination) Gusts24 kt Ceiling500 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 939 · LHR → SFO

Odds over time

How late will it get to SFO?