About 1 in 3 UA 2251 flights from Chicago arrived 15+ minutes late, diverted or cancelled over the past year (34%); 0.0% were cancelled. The typical flight landed 4 minutes late.
UA 2251: ORD → SFO
Scheduled to leave Chicago at 3:57 p.m. local time. Over the past year it arrived on time 66% of the time (131 flights), in line with other UA flights on the route at that hour (64%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 20 | 60% |
| Tuesday | 19 | — |
| Wednesday | 19 | — |
| Thursday | 19 | — |
| Friday | 19 | — |
| Saturday | 15 | — |
| Sunday | 20 | 75% |
Why it was late
All flights ORD → SFO · Connecting off UA 2251? Check the risk
Questions
How often is UA 2251 from ORD to SFO late?
United Airlines 2251 from Chicago, IL to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 34% of 131 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check United Airlines for today's flight. Method.