About 1 in 5 UA 604 flights from San Francisco arrived 15+ minutes late, diverted or cancelled over the past year (19%); 0.0% were cancelled. The typical flight landed 5 minutes early.
UA 604: SFO → IAH
Scheduled to leave San Francisco at 12:45 a.m. local time. Over the past year it arrived on time 81% of the time (156 flights), worse than other UA flights on the route at that hour (86%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 23 | 87% |
| Tuesday | 22 | 64% |
| Wednesday | 22 | 82% |
| Thursday | 22 | 86% |
| Friday | 22 | 77% |
| Saturday | 22 | 82% |
| Sunday | 23 | 87% |
Why it was late
All flights SFO → IAH · Connecting off UA 604? Check the risk
UA 604: IAH → BWI
Scheduled to leave Houston at 7:30 a.m. local time. Over the past year it arrived on time 91% of the time (142 flights), in line with other UA flights on the route at that hour (90%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 18 | — |
| Tuesday | 28 | 89% |
| Wednesday | 25 | 92% |
| Thursday | 29 | 100% |
| Friday | 29 | 86% |
| Saturday | 10 | — |
| Sunday | 3 | — |
Why it was late
All flights IAH → BWI · Connecting off UA 604? Check the risk
Questions
How often is UA 604 from SFO to IAH late?
United Airlines 604 from San Francisco, CA to Houston, TX arrived 15 or more minutes late, was diverted or was cancelled on 19% of 156 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
How often is UA 604 from IAH to BWI late?
United Airlines 604 from Houston, TX to Baltimore, MD arrived 15 or more minutes late, was diverted or was cancelled on 9% of 142 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.