ON TIMEBOARD

DEN → ASE on time

Denver (Denver, CO) to Aspen-Pitkin (Sardy ) (Aspen, CO). Every scheduled flight, September 2025 to August 2026.

On time
69%
arrived < 15 min late
Cancelled
5.1%
2,742 flights
Typical arrival
−6 min
median vs schedule
When late
+96 min
average delay
Flights / day
8
1 airline

69% of flights from Denver to Aspen arrived on time over the past 12 months. That is worse than the typical U.S. route. The 7 a.m. departures ran on time 83% of the time; the noon ones 62%. 17% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for DEN → ASE: when a flight was late, it was under 45 minutes late 45% of the time. About 1 in 9 flights landed an hour or more late, and 1 in 52 three hours or more; 5.1% were cancelled outright.

Share of all 2,742 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines2,74269%5.1%−6 min10.8%+96 minSkyWest

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at DEN). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%7 a.m. departures: 83% on time (127 flights)837a8 a.m. departures: 76% on time (121 flights)768a9 a.m. departures: 70% on time (264 flights)709a10 a.m. departures: too few flights (49 flights)10a11 a.m. departures: 71% on time (305 flights)7111anoon departures: 62% on time (101 flights)6212p1 p.m. departures: 67% on time (336 flights)671p2 p.m. departures: too few flights (18 flights)2p3 p.m. departures: 70% on time (288 flights)703p4 p.m. departures: 63% on time (187 flights)634p5 p.m. departures: 67% on time (324 flights)675p6 p.m. departures: too few flights (3 flights)6p7 p.m. departures: 65% on time (336 flights)657p8 p.m. departures: 71% on time (281 flights)718p
DEN → ASE, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On DEN → ASE, each airline's last flight of the day was cancelled 5.6% of the time, against 5.0% for its earlier flights, about the same. It arrived 3+ hours late 3.6% of the time (earlier flights: 1.7%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
United Airlines8:25 p.m.5.6%3.6%5.0%first flight 7:45 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

By month

Each calendar month pooled over 2023–2026. Best: May (80%). Worst: June (60%).

40%70%100%Jan: 68% on time (781 flights)68JanFeb: 61% on time (757 flights)61FebMar: 67% on time (893 flights)67MarApr: 77% on time (715 flights)77AprMay: 80% on time (213 flights)80MayJun: 60% on time (706 flights)60JunJul: 61% on time (744 flights)61JulAug: 62% on time (754 flights)62AugSep: 79% on time (654 flights)79SepOct: 80% on time (644 flights)80OctNov: 72% on time (593 flights)72NovDec: 64% on time (774 flights)64Dec

By day of week

DayFlightsOn timeCancelled
Monday41270%3.6%
Tuesday37979%3.7%
Wednesday38173%6.0%
Thursday39668%3.3%
Friday40167%9.7%
Saturday37564%5.1%
Sunday39865%4.3%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 28%Air traffic & airport (NAS) 26%Airline (crew, maintenance, ops) 24%Severe weather 22%

Cancellations: weather 124 · air traffic/airport 15 · airline 1

Month by month

40%70%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 79% on time, 0.0% cancelledOct 2023: 72% on time, 8.1% cancelledNov 2023: 71% on time, 6.2% cancelledDec 2023: 62% on time, 7.9% cancelledJan 2024: 59% on time, 8.9% cancelledFeb 2024: 56% on time, 10.5% cancelledMar 2024: 58% on time, 10.7% cancelledApr 2024: 73% on time, 5.7% cancelledMay 2024: 74% on time, 1.9% cancelledJun 2024: 70% on time, 9.6% cancelledJul 2024: 76% on time, 0.8% cancelledAug 2024: 71% on time, 0.0% cancelledSep 2024: 79% on time, 1.3% cancelledOct 2024: 84% on time, 0.8% cancelledNov 2024: 64% on time, 11.1% cancelledDec 2024: 70% on time, 5.8% cancelledJan 2025: 71% on time, 2.5% cancelledFeb 2025: 61% on time, 9.8% cancelledMar 2025: 66% on time, 8.6% cancelledApr 2025: 74% on time, 4.8% cancelledJun 2025: 53% on time, 3.0% cancelledJul 2025: 54% on time, 6.5% cancelledAug 2025: 59% on time, 4.1% cancelledSep 2025: 79% on time, 0.0% cancelledOct 2025: 82% on time, 0.0% cancelledNov 2025: 83% on time, 4.5% cancelledDec 2025: 59% on time, 5.2% cancelledJan 2026: 73% on time, 8.0% cancelledFeb 2026: 65% on time, 11.4% cancelledMar 2026: 75% on time, 9.7% cancelledApr 2026: 83% on time, 2.8% cancelledJun 2026: 57% on time, 3.9% cancelledJul 2026: 53% on time, 5.5% cancelledAug 2026: 57% on time, 3.8% cancelled
Share of flights on time, by month (hover a point for cancellations)
DEN → ASE, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
UA 54447:45 a.m.20579%2.9%−10 minSkyWest
UA 57829:50 a.m.29476%2.4%−9 minSkyWest
UA 576911:33 a.m.33670%3.0%+1 minSkyWest
UA 57711:40 p.m.33667%4.5%−5 minSkyWest
UA 57733:35 p.m.30671%6.5%−9 minSkyWest
UA 56974:22 p.m.12357%8.1%0 minSkyWest
UA 57755:25 p.m.33167%6.0%−7 minSkyWest
UA 57797:10 p.m.33565%4.8%−1 minSkyWest
UA 57818:25 p.m.28171%6.8%−8 minSkyWest

Worst days in the past year

DateFlightsOn timeCancelled
Mar 6, 2026100%10
Jan 4, 2026100%0
Dec 27, 2025100%3
Feb 20, 2026100%6
Dec 3, 202580%3

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Denver or Aspen. DEN → GUC has been 10 points more reliable.

RouteFlightsOn timeCancelled
DEN → ASE (this route)2,74269%5.1%
DEN → GUC Denver to Gunnison Crested Butte99480%0.8%
DEN → EGE Denver to Eagle1,17179%0.3%

Questions

How often are flights from DEN to ASE on time?

69% of 2,742 scheduled flights from Denver, CO to Aspen, CO arrived within 15 minutes of schedule between September 2025 and August 2026. 5.1% were cancelled.

What is the best time of day to fly DEN to ASE?

Flights scheduled to leave at 7 a.m. were the most reliable (83% on time). The noon departures were the least (62%).

What month has the most delays from DEN to ASE?

June (60% on time). The best month is May (80%), over 2023–2026.

Is the last flight of the day from DEN to ASE more likely to be cancelled?

Not much. Each airline's last DEN–ASE flight of the day was cancelled 5.6% of the time over the past year, against 5.0% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.