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.

SOUTHWEST · FLIGHT WN 3421 LANDED 1:57 PM PT, ~7 MIN LATE · SCHEDULED TIME UNKNOWN

Tuesday, September 29 Today

WN 3421 · DEN → SMF

took off 12:56 PM MT · landed 1:57 PM PT (scheduled time unknown)

Forecast issued Tue 4:00 PM ET · 1h after departure

Arrive at SMF more than 15 minutes late?

30% chance · ±0 pts – · 24h

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

What’s moving the odds

↑ This flight has been late 33% of the time recently

↑ Other factors

↑ 12pm departures from DEN are often late

↓ Tuesdays in September are usually quieter than average

↓ Mostly benign weather forecast at SMF

Weather at each end

DEN (origin) Gusts9 kt Ceiling6,000 ft Visibility10+ mi Precipnone

SMF (destination) Gusts16 kt Ceilingnone (clear) Visibility9 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.

WN 3421 · DEN → SMF

Odds over time