Route reliability record

CLT→DEN

Charlotte to Denver

Flights: 2,816
Period: July 2025 to June 2026
Distance: 1,337 mi
Carriers: 5

This route lands a B, level with the national rate of 77.6%. Roughly one flight in four arrive 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 2,816 flights, of which United Airlines flew 675 at 85.1% on time.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

77.0%

Arrivals under 15 minutes late, of 2,771 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.28%

National rate is 1.81%

Best carrier

United

85.1% on time across 675 flights

These figures cover 2,816 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% 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 CLT to DEN

The choice of carrier is not cosmetic here. United Airlines arrives on time 85.1% of the time; American Airlines manages 75.1%. Sample sizes sit next to every figure, because a two-point gap across 1,717 flights means less than a ten-point one.

On-time performance by carrier on CLT to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	675	85.1%	79 min	1.19%	A
SkyWest Airlinesthin sample	20	84.2%	214 min	5.00%	B−
Frontier Airlinesthin sample	215	76.9%	56 min	1.40%	B
American Airlines	1,717	75.1%	61 min	1.22%	B
Southwest Airlinesthin sample	189	65.6%	52 min	1.59%	C

United leads American by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 23 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am166 flights87.2%
8am–11am620 flights90.0%
11am–2pm574 flights81.4%
2pm–5pm501 flights71.4%
5pm–8pm629 flights67.1%
8pm–5am326 flights67.5%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 90.0% of the time, against 67.1% for the evening window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 629 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 30 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.

Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 58.1% on time, 30 points below January, the best at 87.9%. 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. July was the busiest month here, with 254 flights.

Across the week, Wednesday is the strongest day at 83.9% on time and Thursday the weakest at 73.2%. 11 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 40,000 reported delay minutes.

Late-arriving aircraft
39%
Carrier
29%
National Airspace System
29%
Extreme weather
3%
Security
0%

39% 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 40,000 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 40,315 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.0% on time here.

Cancellations sit at 1.28% against a national 1.81%, which is ordinary. Diversions add another 0.32%.

Connections and stage length

What a delay here actually costs

8.4% 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 are the about an hour kind, which a normal layover absorbs.

The 1,337 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 82.4% on time across 2,813 flights, 5 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 5 points of difference.

The sample behind these figures is 2,816 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 this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 87.9% on time and July 58.1%, a swing of 30 points. If the dates move at all, move them out of July before you think about anything else. 2,771 completed flights over 12 months sit behind that.

Common questions

CLT to DEN questions

How often is CLT to DEN delayed?

Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.0% of the 2,816 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on CLT to DEN?

United Airlines leads at 85.1% on time across 675 flights. American Airlines is at the other end on 75.1%, a gap of 10 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on CLT to DEN?

The 8am–11am departure window is the strongest at 90.0% on time. The 5pm–8pm window is the weakest at 67.1%, 23 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 July delays on CLT to DEN?

July is the weakest month at 58.1% on time, compared with 87.9% in January. Across the year that is 30 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. CLT to DEN and DEN to CLT are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures