Route reliability record

MCI→DEN

Kansas City to Denver

Flights: 4,274
Period: July 2025 to June 2026
Distance: 533 mi
Carriers: 4

This route lands a B+, 2 points worse than the national rate of 77.6%. About 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 4,274 flights, of which SkyWest Airlines flew 374 at 89.5% on time.

SkyWest Airlines is the most reliable of the three carriers covered here at 89.5% on time across 374 flights.

On time

76.1%

Arrivals under 15 minutes late, of 4,236 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

0.61%

National rate is 1.81%

Best carrier

SkyWest

89.5% on time across 374 flights

These figures cover 4,274 flights between July 2025 and June 2026. The median arrival is 2 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

Which airline is most reliable on MCI to DEN

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.5% of the time; Southwest Airlines manages 73.0%. Sample sizes sit next to every figure, because a two-point gap across 2,341 flights means less than a ten-point one.

On-time performance by carrier on MCI to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	374	89.5%	104 min	0.27%	A+
United Airlines	1,298	77.8%	61 min	0.54%	B+
Frontier Airlinesthin sample	261	75.8%	119 min	0.38%	B+
Southwest Airlines	2,341	73.0%	58 min	0.73%	C+

The spread between SkyWest and Southwest is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.

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 31 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am748 flights91.4%
8am–11am804 flights78.7%
11am–2pm906 flights84.4%
2pm–5pm648 flights67.4%
5pm–8pm900 flights60.7%
8pm–5am268 flights69.3%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 60.7% on time, against 91.4% 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 906 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 24 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 61.8% on time, 24 points below January, the best at 85.3%. 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. June was the busiest month here, with 420 flights.

Across the week, Tuesday is the strongest day at 79.8% on time and Monday the weakest at 73.3%. 7 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 66,000 reported delay minutes.

Late-arriving aircraft
37%
National Airspace System
36%
Carrier
22%
Extreme weather
5%
Security
0%

37% 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 66,000 reported delay minutes here, that single category outweighs weather by 8 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 65,526 reported delay minutes.

36% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 24,000 minutes out of 66,000, against a national NAS share of 21%.

Cancellations are rare at 0.61%, 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 actually costs

7.8% 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 533 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 75.5% on time across 4,269 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 4,274 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 85.3% on time and July 61.8%, a swing of 24 points. If the dates move at all, move them out of July before you think about anything else. 4,236 completed flights over 12 months sit behind that.

Common questions

MCI to DEN questions

How often is MCI to DEN delayed?

About 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 23.9% of the 4,274 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on MCI to DEN?

SkyWest Airlines leads at 89.5% on time across 374 flights. Southwest Airlines is at the other end on 73.0%, a gap of 17 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 MCI to DEN?

The 5am–8am departure window is the strongest at 91.4% on time. The 5pm–8pm window is the weakest at 60.7%, 31 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 MCI to DEN?

July is the weakest month at 61.8% on time, compared with 85.3% in January. Across the year that is 24 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. MCI to DEN and DEN to MCI 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