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DelayAtlas

Carrier route record

UAGTFDEN

United Airlines · Great Falls to Denver

Flights
528
Period
July 2025 to June 2026
Share of route
72%
Carriers
2
B+GRADE

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

United on GTF to DEN lands a B+, 6 points better than the national rate of 77.6%. About one flight in six 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 528 flights, with a median arrival 14 minutes early.

Set against the rest of the country, United's GTF to DEN record is 6 points better than the US average of 77.6%. That gap is worth roughly 57 fewer late arrivals for every thousand flights.

Key figures

On time

83.3%

Arrivals under 15 minutes late, of 521 completed flights

Avg delay

86 min

Across delayed arrivals only, not all flights

Cancelled

0.95%

National rate is 1.81%

Whole route

85.6%

Every carrier on GTF to DEN, 729 flights

These figures cover 528 flights between July 2025 and June 2026. The median arrival is 14 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 GTF to DEN

United flew 528 of the 729 flights on GTF to DEN, most of the route. Its 83.3% on time is 2 points worse than the route as a whole, which runs 85.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 91.5% to United at 83.3%. 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 GTF to DEN
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlinesthin sample20191.5%121 min1.00%A
United Airlines (this page)52883.3%86 min0.95%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 16 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–8am238 flights92.3%
  • 8am–11am
  • 11am–2pm
  • 2pm–5pm290 flights75.9%
  • 5pm–8pm
  • 8pm–5am

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.3% of the time, against 75.9% for the afternoon window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 290 flights scheduled in it.

Across the year

United on GTF to DEN through the year

On-time rate by calendar monthJF90M92A87M73J77J72A85S84O91ND
Darker means more delays. Figures are on-time percentages.April best, August worst

August is the worst month at 72.1% on time, 20 points below April, the best at 91.7%. 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. May was the busiest month here, with 62 flights.

Across the week, Sunday is the strongest day at 86.8% on time and Friday the weakest at 76.6%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week84.0Mon82.7Tue85.9Wed80.8Thu76.6Fri86.5Sat86.8Sun
Monday: 84.0 percent on time. Tuesday: 82.7 percent on time. Wednesday: 85.9 percent on time. Thursday: 80.8 percent on time. Friday: 76.6 percent on time. Saturday: 86.5 percent on time. Sunday: 86.8 percent on time

Delay causes

Why United runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,478 reported delay minutes.

  • National Airspace System
    38%
  • Late-arriving aircraft
    23%
  • Extreme weather
    21%
  • Carrier
    19%

Extreme weather accounts for 21% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.3 times the usual weather exposure. The split is drawn from 7,478 reported delay minutes.

38% 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 2,810 minutes out of 7,478, against a national NAS share of 21%.

Cancellations sit at 0.95% against a national 1.81%, which is ordinary. Diversions add another 0.38%.

Connections and stage length

What a delay here costs

7.3% 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 an hour and a half, which a normal layover absorbs.

The 623 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 74.5% on time across 528 flights, 9 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 9 points of difference.

One caution: this is a thin sample. 528 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 GTF to DEN

Put together: treat all of this as provisional. 528 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 83.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 521 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.