Schedule: the flights that flew on Wednesday, Oct 21, re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
UNITED · FLIGHT UA 3921SCHEDULED · TYPICAL SCHEDULE
Tomorrow
UA 3921 · PHX → SEA
departs 12:33 PM MT · arrives 3:48 PM PT
Forecast issued Tue 4:00 AM ET · 36h before departure
Odds over time
Arrive at SEA more than 15 minutes late?
20%chance · ±1 pts+0 pts · 24h
HOW SURE WE AREModerate. The odds now blend history with early weather forecasts.
How late will it get to SEA?
On time or early
79%
15–30 min late
8%
30 min–1 hour late
7%
1–2 hours late
2%
Over 2 hours late
2%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.