About 1 in 5 UA 1840 flights from Denver arrived 15+ minutes late, diverted or cancelled over the past year (18%); 0.6% were cancelled. The typical flight landed 6 minutes early.
UA 1840: DEN → SLC
Scheduled to leave Denver at 1:40 p.m. local time. Over the past year it arrived on time 82% of the time (174 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 | 26 | 85% |
| Tuesday | 24 | 88% |
| Wednesday | 24 | 92% |
| Thursday | 25 | 88% |
| Friday | 25 | 68% |
| Saturday | 24 | 75% |
| Sunday | 26 | 77% |
Why it was late
All flights DEN → SLC · Connecting off UA 1840? Check the risk
Questions
How often is UA 1840 from DEN to SLC late?
United Airlines 1840 from Denver, CO to Salt Lake City, UT arrived 15 or more minutes late, was diverted or was cancelled on 18% of 174 scheduled flights between September 2025 and August 2026. 0.6% 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.