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 4121 LANDED 3:23 PM MT, ~10 MIN LATE · SCHEDULED TIME UNKNOWN

Tuesday, September 29 Today

WN 4121 · PHX → SLC

took off 1:18 PM MT · landed 3:23 PM MT (scheduled time unknown)

Forecast issued Tue 4:00 PM ET · 0h before departure

Arrive at SLC more than 15 minutes late?

32% chance · ±1 pts −6 pts · 24h

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

What’s moving the odds

↑ 1pm departures from PHX are often late

↑ Other factors

↑ This flight has been late 30% of the time recently

↓ Tuesdays in September are usually quieter than average

↓ Mostly benign weather forecast at SLC

Weather at each end

PHX (origin) Gusts20 kt Ceiling1,800 ft Visibility1.75 mi Precip0.67 in

SLC (destination) Gusts16 kt Ceiling6,500 ft Visibility10+ 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 4121 · PHX → SLC

Odds over time