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 2021SCHEDULED · TYPICAL SCHEDULE
Tomorrow
UA 2021 · IAD → SJU
departs 8:34 AM ET · arrives 12:34 PM AT
Forecast issued Sun 12:00 AM ET · 33h before departure
Odds over time
Arrive at SJU more than 15 minutes late?
9%chance · ±1 pts−1 pt · 24h
HOW SURE WE AREModerate. The odds now blend history with early weather forecasts.
How late will it get to SJU?
On time or early
90%
15–30 min late
3%
30 min–1 hour late
4%
1–2 hours late
1%
Over 2 hours late
1%
Cancelled
<1%
Gate arrival compared with the scheduled arrival. The ranges add up to 100%.