About 1 in 5 UA 2278 flights from San Francisco arrived 15+ minutes late, diverted or cancelled over the past year (18%); 2.0% were cancelled. The typical flight landed 14 minutes early.
UA 2278: SFO → ORD
Scheduled to leave San Francisco at 10:35 p.m. local time. Over the past year it arrived on time 82% of the time (201 flights), in line with other UA flights on the route at that hour (82%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 29 | 83% |
| Tuesday | 28 | 93% |
| Wednesday | 28 | 82% |
| Thursday | 29 | 72% |
| Friday | 29 | 79% |
| Saturday | 29 | 79% |
| Sunday | 29 | 83% |
Why it was late
All flights SFO → ORD · Connecting off UA 2278? Check the risk
UA 2278: SAN → SFO
Scheduled to leave San Diego at 7:41 p.m. local time. Over the past year it arrived on time 35% of the time (155 flights), worse than other UA flights on the route at that hour (44%). Last seen in the data Aug 31, 2026.
Usually United Airlines's last flight of the day from San Diego to San Francisco (100% of days). United Airlines's last SAN–SFO flight was cancelled 1.1% of the time, against 0.5% for its earlier ones. If it's cancelled, the next United Airlines flight is usually around 6:20 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 26 | 23% |
| Tuesday | 8 | — |
| Wednesday | 22 | 14% |
| Thursday | 29 | 34% |
| Friday | 28 | 43% |
| Saturday | 14 | — |
| Sunday | 28 | 21% |
Why it was late
All flights SAN → SFO · Connecting off UA 2278? Check the risk
Questions
How often is UA 2278 from SFO to ORD late?
United Airlines 2278 from San Francisco, CA to Chicago, IL arrived 15 or more minutes late, was diverted or was cancelled on 18% of 201 scheduled flights between September 2025 and August 2026. 2.0% were cancelled.
How often is UA 2278 from SAN to SFO late?
United Airlines 2278 from San Diego, CA to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 65% of 155 scheduled flights between September 2025 and August 2026. 0.7% 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.