Carrier route record
AAMIA→DEN
American Airlines · Miami to Denver
- Flights
- 885
- Period
- July 2025 to June 2026
- Share of route
- 36%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with American Airlines.
American on MIA to DEN sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 885 flights, with a median arrival 6 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate American on MIA to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.7%
Arrivals under 15 minutes late, of 874 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.79%
National rate is 1.81%
Whole route
77.1%
Every carrier on MIA to DEN, 2,491 flights
These figures cover 885 flights between July 2025 and June 2026. The median arrival is 6 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
American against every carrier on MIA to DEN
American flew 885 of the 2,491 flights on MIA to DEN, about 36% of it. Its 75.7% on time is about level with the route as a whole at 77.1%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from Frontier at 82.8% to Southwest at 59.7%. Two 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 351 | 82.8% | 112 min | 1.42% | B |
| United Airlines | 932 | 82.1% | 68 min | 0.11% | B+ |
| American Airlines (this page) | 885 | 75.7% | 63 min | 0.79% | B+ |
| Southwest Airlinesthin sample | 323 | 59.7% | 57 min | 0.00% | D+ |
Departure window
When American 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–8am—
- 8am–11am327 flights84.3%
- 11am–2pm37 flights80.0%
- 2pm–5pm—
- 5pm–8pm156 flights75.2%
- 8pm–5am365 flights67.9%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 84.3% of the time, against 67.9% for the overnight 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 8pm–5am window is the busiest, with 365 flights scheduled in it.
Across the year
American on MIA to DEN through the year
August is the worst month at 71.0% on time, 9 points below October, the best at 80.3%. 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. January was the busiest month here, with 93 flights.
Across the week, Tuesday is the strongest day at 80.0% on time and Sunday the weakest at 71.2%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why American runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 13,000 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.
- 43%Late-arriving aircraft
- 39%Carrier
- 14%National Airspace System
- 4%Extreme weather
- 1%Security
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 13,000 reported delay minutes here, that single category outweighs weather by 12 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 13,335 reported delay minutes.
The largest share of delay minutes, 39%, 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 5,159 of the 13,000 delay minutes reported here.
Cancellations are rare at 0.79%, 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
7.0% 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.
At 1,709 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg runs 76.6% on time across 886 flights, within about a point 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. 885 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 American on MIA to DEN
Put together: treat all of this as provisional. 885 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 75.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 874 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to DEN, every carrier
- American on DEN to MIA, the return leg
- Frontier Airlines on MIA to DEN82.8%
- United Airlines on MIA to DEN82.1%
- Southwest Airlines on MIA to DEN59.7%
- American Airlines network-wide record
- Miami International (MIA) delay statistics
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.