About 1 in 6 UA 660 flights from Chicago arrived 15+ minutes late, diverted or cancelled over the past year (18%); 0.0% were cancelled. The typical flight landed 11 minutes early.
UA 660: ORD → SAN
Scheduled to leave Chicago at 8:46 a.m. local time. Over the past year it arrived on time 82% of the time (365 flights), in line with other UA flights on the route at that hour (83%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 83% |
| Tuesday | 52 | 90% |
| Wednesday | 52 | 87% |
| Thursday | 52 | 79% |
| Friday | 52 | 79% |
| Saturday | 52 | 83% |
| Sunday | 52 | 75% |
Why it was late
All flights ORD → SAN · Connecting off UA 660? Check the risk
UA 660: PHL → ORD
Scheduled to leave Philadelphia at 6:00 a.m. local time. Over the past year it arrived on time 82% of the time (160 flights), in line with other UA flights on the route at that hour (83%). Last seen in the data Aug 10, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 25 | 72% |
| Tuesday | 20 | 80% |
| Wednesday | 19 | — |
| Thursday | 23 | 96% |
| Friday | 24 | 67% |
| Saturday | 24 | 79% |
| Sunday | 25 | 84% |
Why it was late
All flights PHL → ORD · Connecting off UA 660? Check the risk
Questions
How often is UA 660 from ORD to SAN late?
United Airlines 660 from Chicago, IL to San Diego, CA arrived 15 or more minutes late, was diverted or was cancelled on 18% of 365 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
How often is UA 660 from PHL to ORD late?
United Airlines 660 from Philadelphia, PA to Chicago, IL arrived 15 or more minutes late, was diverted or was cancelled on 18% of 160 scheduled flights between September 2025 and August 2026. 5.6% 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.