Carrier route record

UAMTJ→DEN

United Airlines · Montrose to Denver

Flights: 886
Period: July 2025 to June 2026
Share of route: 63%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.

United on MTJ to DEN 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 an hour and a half on average. That is a workable record, not a spotless one. That rests on 886 flights, with a median arrival 8 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate United on MTJ to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

78.5%

Arrivals under 15 minutes late, of 879 completed flights

Avg delay

93 min

Across delayed arrivals only, not all flights

Cancelled

0.68%

National rate is 1.81%

Whole route

78.9%

Every carrier on MTJ to DEN, 1,416 flights

These figures cover 886 flights between July 2025 and June 2026. Beyond the headline rate, 9.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

United against every carrier on MTJ to DEN

United flew 886 of the 1,416 flights on MTJ to DEN, most of the route. Its 78.5% on time is about level with the route as a whole at 78.9%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Southwest at 80.7% to SkyWest at 75.7%. 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.

On-time performance by carrier on MTJ to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	420	80.7%	80 min	0.24%	B+
United Airlines (this page)	886	78.5%	93 min	0.68%	B+
SkyWest Airlinesthin sample	110	75.7%	68 min	0.91%	B+

Departure window

When United runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am365 flights85.4%
8am–11am—
11am–2pm314 flights83.3%
2pm–5pm207 flights59.0%
5pm–8pm—
8pm–5am—

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 85.4% of the time, against 59.0% for the afternoon window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 365 flights scheduled in it.

Across the year

United on MTJ to DEN through the year

Darker means more delays. Figures are on-time percentages.November best, July worst

July is the worst month at 60.7% on time, 36 points below November, the best at 96.6%. 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. March was the busiest month here, with 93 flights.

Across the week, Wednesday is the strongest day at 84.7% on time and Friday the weakest at 72.8%. 12 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 43% of the 18,000 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.

Late-arriving aircraft
43%
National Airspace System
34%
Carrier
21%
Extreme weather
2%

43% 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 18,000 reported delay minutes here, that single category outweighs weather by 20 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 17,555 reported delay minutes.

34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 6,016 minutes out of 18,000, against a national NAS share of 21%.

Cancellations are rare at 0.68%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 197 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 74.6% on time across 886 flights, 4 points below 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. 886 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 MTJ to DEN

Put together: treat all of this as provisional. 886 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 78.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 879 completed flights over 12 months sit behind that.

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.

Key figures