About 1 in 3 UA 1236 flights from Denver arrived 15+ minutes late, diverted or cancelled over the past year (34%); 0.5% were cancelled. The typical flight landed 3 minutes early.
UA 1236: DEN → PHX
Scheduled to leave Denver at 8:59 p.m. local time. Over the past year it arrived on time 66% of the time (210 flights), in line with other UA flights on the route at that hour (64%). Last seen in the data Aug 30, 2026.
Usually United Airlines's last flight of the day from Denver to Phoenix (100% of days). United Airlines's last DEN–PHX flight was cancelled 0.3% of the time, against 0.3% for its earlier ones. If it's cancelled, the next United Airlines flight is usually around 8:00 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 30 | 53% |
| Tuesday | 2 | — |
| Wednesday | 41 | 73% |
| Thursday | 44 | 66% |
| Friday | 44 | 64% |
| Saturday | 8 | — |
| Sunday | 41 | 66% |
Why it was late
All flights DEN → PHX · Connecting off UA 1236? Check the risk
Questions
How often is UA 1236 from DEN to PHX late?
United Airlines 1236 from Denver, CO to Phoenix, AZ arrived 15 or more minutes late, was diverted or was cancelled on 34% of 210 scheduled flights between September 2025 and August 2026. 0.5% 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.