Carrier route record
F9DTW→DEN
Frontier Airlines · Detroit to Denver
- Flights
- 459
- Period
- July 2025 to June 2026
- Share of route
- 15%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier 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 459 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
83.2%
Arrivals under 15 minutes late, of 457 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
0.44%
National rate is 1.81%
Whole route
79.7%
Every carrier on DTW to DEN, 3,089 flights
These figures cover 459 flights between July 2025 and June 2026. The median arrival is 9 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
Frontier against every carrier on DTW to DEN
Frontier flew 459 of the 3,089 flights on DTW to DEN, about 15% of it. Its 83.2% on time is 4 points better than the route as a whole, which runs 79.7%. Ranked by on-time rate it is number three 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 (this page) | 459 | 83.2% | 73 min | 0.44% | B+ |
| Delta Air Lines | 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.
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am122 flights87.7%
- 8am–11am84 flights85.7%
- 11am–2pm169 flights85.7%
- 2pm–5pm7 flights—
- 5pm–8pm35 flights71.4%
- 8pm–5am42 flights63.4%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.4% on time, against 87.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 169 flights scheduled in it.
Across the year
Frontier on DTW to DEN through the year
December is the weak month at 46.9% on time, against 93.9% in August. 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. June was the busiest month here, with 60 flights.
Across the week, Wednesday is the strongest day at 94.9% on time and Saturday the weakest at 76.0%. 19 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Carrier accounts for 45% of the 5,588 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.
- 45%Carrier
- 31%Late-arriving aircraft
- 23%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 45%, 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 2,499 of the 5,588 delay minutes reported here. The split is drawn from 5,588 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.7% on time here.
Cancellations are rare at 0.44%, 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
6.3% 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 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 runs 80.3% on time across 459 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 459 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 Frontier on DTW to DEN
Put together: treat all of this as provisional. 459 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 83.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 457 completed flights over 12 months sit behind that.
Related
Where to go next
- DTW to DEN, every carrier
- Frontier on DEN to DTW, the return leg
- United Airlines on DTW to DEN83.7%
- Delta Air Lines on DTW to DEN78.6%
- Southwest Airlines on DTW to DEN74.7%
- Frontier Airlines 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.