Carrier route record
UADEN→MSO
United Airlines · Denver to Missoula
- Flights
- 717
- Period
- September 2025 to August 2026
- Share of route
- 60%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to MSO lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That rests on 717 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.3%, 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
79.2%
Arrivals under 15 minutes late, of 713 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
0.14%
National rate is 1.89%
Whole route
81.5%
Every carrier on DEN to MSO, 1,198 flights
These figures cover 717 flights between September 2025 and August 2026. The median arrival is 2 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.
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Carrier by carrier
United against every carrier on DEN to MSO
United flew 717 of the 1,198 flights on DEN to MSO, most of the route. Its 79.2% on time is 2 points worse than the route as a whole, which runs 81.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 85.0% to Frontier at 75.0%. 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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 473 | 85.0% | 68 min | 0.63% | A+ |
| United Airlines (this page) | 717 | 79.2% | 52 min | 0.14% | B+ |
| Frontier Airlinesthin sample | 8 | 75.0% | 49 min | 0.00% | B+ |
Flight by flight
United flight numbers on DEN to MSO
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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 717 flights.
- 5am–8am—
- 8am–11am—
- 11am–2pm359 flights83.5%
- 2pm–5pm1 flights—
- 5pm–8pm357 flights74.9%
- 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 83.5% on time, ahead of 5pm–8pm at 74.9%. 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
August is the worst month at 62.9% 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 83.3% on time and Monday the weakest at 75.5%, a spread of 8 points.
Arrival by arrival
How late United on DEN to MSO runs when it is late
The 148 late arrivals split 72 under half an hour, 37 between 30 and 60 minutes, and 39 an hour or more.
- 15+ min early113 flights15.8%
- Within 15 min452 flights63.4%
- 15–29 min late72 flights10.1%
- 30–59 min late37 flights5.2%
- 1–2 hours late22 flights3.1%
- 2+ hours late17 flights2.4%
Scale runs 0% to 100%.
Share of 713 completed flights by arrival against schedule.
21 of 131 late departures made up the time and arrived on time, 16% of them. In the other direction, 38 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at MSO.
The worst days
Worst days for United on DEN to MSO
The latest arrival of the period was on 10 January 2026, 4 hours 33 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 January 2026 | 4 hours 33 minutes | Late-arriving aircraft |
| 26 September 2025 | 3 hours 10 minutes | Late-arriving aircraft |
| 24 August 2026 | 3 hours 8 minutes | Late-arriving aircraft |
| 28 July 2026 | 3 hours 6 minutes | Carrier |
| 10 August 2026 | 2 hours 56 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 46% of the 7,635 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Late-arriving aircraft
- 35%Carrier
- 18%National Airspace System
- 1%Extreme weather
46% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,635 reported delay minutes here, that single category outweighs weather by 46 to one. The split is drawn from 7,635 reported delay minutes.
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,654 of the 7,635 delay minutes reported here.
Cancellations are rare at 0.14%, below the national 1.89% 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
5.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, 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.
The return leg is a different operation and performs like one: it runs 83.1% on time across 717 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 717 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. 717 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 79.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 713 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to MSO, every carrier
- United on MSO to DEN, the return leg
- SkyWest Airlines on DEN to MSO85.0%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.