About 1 in 7 UA 2638 flights from Chicago arrived 15+ minutes late, diverted or cancelled over the past year (14%); 0.0% were cancelled. The typical flight landed 14 minutes early.
UA 2638: ORD → IAH
Scheduled to leave Chicago at 10:35 a.m. local time. Over the past year it arrived on time 86% of the time (259 flights), in line with other UA flights on the route at that hour (84%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 38 | 89% |
| Tuesday | 36 | 83% |
| Wednesday | 36 | 86% |
| Thursday | 37 | 95% |
| Friday | 37 | 76% |
| Saturday | 37 | 89% |
| Sunday | 38 | 82% |
Why it was late
All flights ORD → IAH · Connecting off UA 2638? Check the risk
UA 2638: RDU → ORD
Scheduled to leave Raleigh at 6:15 a.m. local time. Over the past year it arrived on time 87% of the time (135 flights), in line with other UA flights on the route at that hour (89%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 25 | 88% |
| Tuesday | 4 | — |
| Wednesday | 13 | — |
| Thursday | 25 | 92% |
| Friday | 25 | 76% |
| Saturday | 18 | — |
| Sunday | 25 | 88% |
Why it was late
All flights RDU → ORD · Connecting off UA 2638? Check the risk
UA 2638: IAH → SEA
Scheduled to leave Houston at 4:25 p.m. local time. Over the past year it arrived on time 70% of the time (123 flights), worse than other UA flights on the route at that hour (78%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 18 | — |
| Tuesday | 17 | — |
| Wednesday | 17 | — |
| Thursday | 18 | — |
| Friday | 18 | — |
| Saturday | 17 | — |
| Sunday | 18 | — |
Why it was late
All flights IAH → SEA · Connecting off UA 2638? Check the risk
Questions
How often is UA 2638 from ORD to IAH late?
United Airlines 2638 from Chicago, IL to Houston, TX arrived 15 or more minutes late, was diverted or was cancelled on 14% of 259 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
How often is UA 2638 from RDU to ORD late?
United Airlines 2638 from Raleigh/Durham, NC to Chicago, IL arrived 15 or more minutes late, was diverted or was cancelled on 13% of 135 scheduled flights between September 2025 and August 2026. 2.2% were cancelled.
How often is UA 2638 from IAH to SEA late?
United Airlines 2638 from Houston, TX to Seattle, WA arrived 15 or more minutes late, was diverted or was cancelled on 30% of 123 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.