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DelayAtlas

Carrier route record

UADTWDEN

United Airlines · Detroit to Denver

Flights
727
Period
July 2025 to June 2026
Share of route
24%
Carriers
5
B+GRADE

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

United on DTW 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 727 flights. The strongest carrier on the route with a full sample, Frontier Airlines, flew 459 at 83.2% on time.

Set against the rest of the country, United's DTW to DEN record is 6 points better than the US average of 77.6%. That gap is worth roughly 61 fewer late arrivals for every thousand flights.

Key figures

On time

83.7%

Arrivals under 15 minutes late, of 713 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

0.69%

National rate is 1.81%

Whole route

79.7%

Every carrier on DTW to DEN, 3,089 flights

These figures cover 727 flights between July 2025 and June 2026. The median arrival is 8 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 DTW to DEN

United flew 727 of the 3,089 flights on DTW to DEN, about 24% of it. Its 83.7% on time is 4 points better than the route as a whole, which runs 79.7%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from SkyWest at 100.0% to Southwest at 74.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Frontier Airlines arrives on time 83.2% of the time; Southwest Airlines manages 74.7%. Sample sizes sit next to every figure, because a two-point gap across 649 flights means less than a ten-point one.

On-time performance by carrier on DTW to DEN
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlinesthin sample1100.0%0.00%A+
United Airlines (this page)72783.7%72 min0.69%B+
Frontier Airlines45983.2%73 min0.44%B+
Delta Air Lines1,25378.6%58 min0.32%B+
Southwest Airlines64974.7%51 min0.62%C+

Frontier leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Flight by flight

United flight numbers on DTW to DEN

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 11 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am365 flights85.5%
  • 11am–2pm
  • 2pm–5pm296 flights83.7%
  • 5pm–8pm66 flights74.2%
  • 8pm–5am

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 85.5% of the time, against 74.2% for the evening window. That is 11 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 365 flights scheduled in it.

Across the year

United on DTW to DEN through the year

On-time rate by calendar month68J84F82M97A89M88J81J86A83S85O93N71D
Darker means more delays. Figures are on-time percentages.April best, January worst

January is the weak month at 67.7% on time, against 96.7% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. January was the busiest month here, with 62 flights.

Across the week, Tuesday is the strongest day at 86.5% on time and Wednesday the weakest at 80.8%. 6 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week84.3Mon86.5Tue80.8Wed83.0Thu84.0Fri83.5Sat84.0Sun
Monday: 84.3 percent on time. Tuesday: 86.5 percent on time. Wednesday: 80.8 percent on time. Thursday: 83.0 percent on time. Friday: 84.0 percent on time. Saturday: 83.5 percent on time. Sunday: 84.0 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 8,316 reported delay minutes.

  • National Airspace System
    38%
  • Carrier
    37%
  • Late-arriving aircraft
    23%
  • Extreme weather
    2%

The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,065 of the 8,316 delay minutes reported here. The split is drawn from 8,316 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 3,194 minutes out of 8,316, against a national NAS share of 21%.

Cancellations are rare at 0.69%, 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

5.5% 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 a little over an hour, which a normal layover absorbs.

The 1,123 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 79.7% on time across 727 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. 727 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 DTW to DEN

Put together: treat all of this as provisional. 727 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 83.7% 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

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.