Route reliability record
ORD→ASE
Chicago to Aspen
- Flights
- 1,072
- Period
- July 2025 to June 2026
- Distance
- 1,013 mi
- Carriers
- 1
This route draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 1,072 ORD to ASE flights, with a median arrival 4 minutes late.
Best time to fly ORD to ASE: a 5pm–8pm departure, ideally on a Wednesday. Flights in that window arrived on time 72.2% of the time and Wednesday flights 69.2%, against 60.6% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 17 points behind the country as a whole. Across a thousand flights that is about 170 extra late arrivals.
Key figures
On time
60.6%
Arrivals under 15 minutes late, of 983 completed flights
Avg delay
96 min
Across delayed arrivals only, not all flights
Cancelled
2.99%
National rate is 1.81%
Best carrier
SkyWest
60.6% on time across 1,072 flights
These figures cover 1,072 flights between July 2025 and June 2026. Beyond the headline rate, 17.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on ORD to ASE
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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 1,072 | 60.6% | 96 min | 2.99% | D |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 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–8am110 flights68.9%
- 8am–11am424 flights58.1%
- 11am–2pm241 flights51.6%
- 2pm–5pm127 flights63.5%
- 5pm–8pm170 flights72.2%
- 8pm–5am—
Scale runs 45% to 80%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 51.6% on time against 72.2% for 5pm–8pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 424 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 37 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 45.4% on time, against 82.2% 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. March was the busiest month here, with 204 flights.
Across the week, Wednesday is the strongest day at 69.2% on time and Friday the weakest at 49.3%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 37,000 reported delay minutes.
- 30%Carrier
- 30%National Airspace System
- 20%Late-arriving aircraft
- 20%Extreme weather
Extreme weather accounts for 20% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.1 times the usual weather exposure. The split is drawn from 37,252 reported delay minutes.
Cancellations run at 2.99%, against 1.81% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 17.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,013 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 62.1% on time across 1,071 flights, within 2 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. 1,072 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.
Work out the risk of missing a connection in ASE after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 2.99% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 5pm–8pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 983 completed flights over 12 months sit behind that.
Common questions
ORD to ASE questions
How often is ORD to ASE delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 39.4% of the 1,072 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is ORD to ASE compared with the rest of the country?
60.6% of flights arrive on time here against a national 77.6%, a difference of 17 points against it. That is worth a D on this site's grading scale.
What time of day has the fewest delays on ORD to ASE?
The 5pm–8pm departure window is the strongest at 72.2% on time. The 11am–2pm window is the weakest at 51.6%, 21 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on ORD to ASE?
December is the weakest month at 45.4% on time, compared with 82.2% in September. Across the year that is 37 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ASE to ORD — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- ORD to LGA, a related route67.3%
- DEN to ASE, a related route74.8%
- ORD to BOS, a related route67.6%
- SkyWest Airlines on-time record60.6%
- The US routes with the most cancellations
- What a cancellation rate actually tells you (and what it hides)
Direction matters. ORD to ASE and ASE to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.