Carrier route record
UADEN→MSO
United Airlines · Denver to Missoula
- Flights
- 718
- Period
- July 2025 to June 2026
- Share of route
- 59%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to MSO lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 718 flights, with a median arrival 3 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to MSO from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.0%
Arrivals under 15 minutes late, of 714 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.14%
National rate is 1.81%
Whole route
80.5%
Every carrier on DEN to MSO, 1,214 flights
These figures cover 718 flights between July 2025 and June 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
United against every carrier on DEN to MSO
United flew 718 of the 1,214 flights on DEN to MSO, most of the route. Its 79.0% on time is 2 points worse than the route as a whole, which runs 80.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Frontier at 85.7% to United at 79.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 22 | 85.7% | 58 min | 0.00% | A+ |
| SkyWest Airlines | 474 | 82.5% | 74 min | 0.63% | B+ |
| United Airlines (this page) | 718 | 79.0% | 56 min | 0.14% | B+ |
Flight by flight
United flight numbers on DEN to MSO
Departure window
When United runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 718 flights.
- 5am–8am—
- 8am–11am—
- 11am–2pm359 flights82.9%
- 2pm–5pm1 flights—
- 5pm–8pm358 flights75.0%
- 8pm–5am—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 82.9% on time, ahead of 5pm–8pm at 75.0%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 11am–2pm window is the busiest, with 359 flights scheduled in it.
Across the year
United on DEN to MSO through the year
June is the worst month at 63.3% on time, 30 points below November, the best at 93.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 83.5% on time and Friday the weakest at 74.3%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 53% of the 8,385 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 53%Late-arriving aircraft
- 31%Carrier
- 15%National Airspace System
- 0%Extreme weather
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 8,385 reported delay minutes here, that single category outweighs weather by 53 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 8,385 reported delay minutes.
Cancellations are rare at 0.14%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
6.3% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 679 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 84.3% on time across 718 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 718 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking United on DEN to MSO
Put together: treat all of this as provisional. 718 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 79.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 714 completed flights over 12 months sit behind that.
Related
Where to go next
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.