Schedule: a typical summer Monday (the flights of Jul 27, 2026), re-dated. Real flights replace these once airlines file their FAA flight plans, usually about a day ahead.
UNITED · FLIGHT UA 1263SCHEDULED · TYPICAL SCHEDULE
UA 1263 · ONT → DEN
departs 1:18 PM PT · arrives 4:38 PM MT
Forecast issued Sat 7:00 AM ET · 57h before departure
Odds over time
Arrive at DEN more than 15 minutes late?
10%chance · ±1 pts– · 24h
HOW SURE WE AREModerate. The odds now blend history with early weather forecasts.
How late will it get to DEN?
On time or early
89%
15–30 min late
3%
30 min–1 hour late
3%
1–2 hours late
3%
Over 2 hours late
2%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.