Carrier route record
DLDTW→DEN
Delta Air Lines · Detroit to Denver
- Flights
- 1,253
- Period
- July 2025 to June 2026
- Share of route
- 41%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on DTW 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 about an hour on average. That is a workable record, not a spotless one. That rests on 1,253 flights. The strongest carrier on the route with a full sample, United Airlines, flew 727 at 83.7% on time.
United Airlines is the most reliable of the three carriers covered here at 83.7% on time across 727 flights.
Key figures
On time
78.6%
Arrivals under 15 minutes late, of 1,243 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.32%
National rate is 1.81%
Whole route
79.7%
Every carrier on DTW to DEN, 3,089 flights
These figures cover 1,253 flights between July 2025 and June 2026. The median arrival is 5 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
Delta against every carrier on DTW to DEN
Delta flew 1,253 of the 3,089 flights on DTW to DEN, about 41% of it. Its 78.6% on time is about level with the route as a whole at 79.7%. Ranked by on-time rate it is number four 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. United Airlines arrives on time 83.7% 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| United Airlines | 727 | 83.7% | 72 min | 0.69% | B+ |
| Frontier Airlines | 459 | 83.2% | 73 min | 0.44% | B+ |
| Delta Air Lines (this page) | 1,253 | 78.6% | 58 min | 0.32% | B+ |
| Southwest Airlines | 649 | 74.7% | 51 min | 0.62% | C+ |
United leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Delta flight numbers on DTW to DEN
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 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–11am366 flights85.5%
- 11am–2pm363 flights85.0%
- 2pm–5pm365 flights71.1%
- 5pm–8pm—
- 8pm–5am159 flights65.2%
Scale runs 55% 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 65.2% for the overnight window. That is 20 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 366 flights scheduled in it.
Across the year
Delta on DTW to DEN through the year
December is the weak month at 62.7% on time, against 92.2% in September. 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. April was the busiest month here, with 116 flights.
Across the week, Wednesday is the strongest day at 80.9% on time and Friday the weakest at 74.5%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta 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 15,000 reported delay minutes.
- 41%Carrier
- 32%National Airspace System
- 20%Late-arriving aircraft
- 7%Extreme weather
The largest share of delay minutes, 41%, 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 6,311 of the 15,000 delay minutes reported here. The split is drawn from 15,456 reported delay minutes.
32% 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 5,005 minutes out of 15,000, against a national NAS share of 21%.
Cancellations are rare at 0.32%, 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
6.5% 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 about 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 86.2% on time across 1,252 flights, 8 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 8 points of difference.
The sample behind these figures is 1,253 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Delta on DTW to DEN
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 92.2% on time and December 62.7%, a swing of 30 points. If the dates move at all, move them out of December before you think about anything else. 1,243 completed flights over 12 months sit behind that.
Related
Where to go next
- DTW to DEN, every carrier
- Delta on DEN to DTW, the return leg
- United Airlines on DTW to DEN83.7%
- Frontier Airlines on DTW to DEN83.2%
- Southwest Airlines on DTW to DEN74.7%
- Delta Air Lines network-wide record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Denver International (DEN) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.