Tracked live by the FAA, but its flight plan was first seen after takeoff, so we don't know the scheduled time and can't say whether it's late.

DELTA · FLIGHT DL 21 LANDED 7:13 PM PT, ~40 MIN LATE · SCHEDULED TIME UNKNOWN

Tuesday, September 29

DL 21 · LHR → SEA

took off 5:50 PM BST · landed 7:13 PM PT (scheduled time unknown)

Forecast issued Tue 10:00 PM ET · 9h after departure

Arrive at SEA more than 15 minutes late?

25% chance · ±0 pts – · 24h

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

What’s moving the odds

↑ Cloud base down to 500 ft forecast at SEA that day

↑ Arrivals into SEA at that hour are often late

↑ Later flights pick up delays from earlier in the day

↓ Other factors

↓ Tuesdays in September are usually quieter than average

Weather at each end

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

SEA (destination) Gusts24 kt Ceiling500 ft Visibility3 mi Precip0.04 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 21 · LHR → SEA

Odds over time