Route reliability record

DSM→DEN

Des Moines to Denver

Flights: 2,329
Period: July 2025 to June 2026
Distance: 589 mi
Carriers: 4

This route lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrive 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 2,329 flights, of which SkyWest Airlines flew 936 at 90.0% on time.

SkyWest Airlines is the most reliable of the three carriers covered here at 90.0% on time across 936 flights.

On time

83.0%

Arrivals under 15 minutes late, of 2,310 completed flights

Avg delay

84 min

Across delayed arrivals only, not all flights

Cancelled

0.60%

National rate is 1.81%

Best carrier

SkyWest

90.0% on time across 936 flights

These figures cover 2,329 flights between July 2025 and June 2026. The median arrival is 9 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 DSM to DEN

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 90.0% of the time; United Airlines manages 74.2%. Sample sizes sit next to every figure, because a two-point gap across 681 flights means less than a ten-point one.

On-time performance by carrier on DSM to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	936	90.0%	101 min	0.75%	A+
Southwest Airlines	559	83.4%	72 min	0.54%	B+
Frontier Airlinesthin sample	153	77.8%	102 min	0.00%	B+
United Airlines	681	74.2%	77 min	0.59%	C+

The spread between SkyWest and United is 16 points, wide enough that it should decide the booking. On a hundred trips that is 16 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 26 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am640 flights91.6%
8am–11am450 flights82.5%
11am–2pm569 flights89.4%
2pm–5pm153 flights82.2%
5pm–8pm474 flights65.2%
8pm–5am43 flights74.4%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.6% of the time, against 65.2% for the evening window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 640 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 16 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.November best, August worst

August is the worst month at 74.4% on time, 16 points below November, the best at 90.6%. 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. August was the busiest month here, with 226 flights.

Across the week, Sunday is the strongest day at 87.3% on time and Friday the weakest at 80.1%. 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 33,000 reported delay minutes.

National Airspace System
34%
Carrier
32%
Late-arriving aircraft
22%
Extreme weather
11%
Security
0%

Extreme weather accounts for 11% 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 1.8 times the usual weather exposure. The split is drawn from 32,899 reported delay minutes.

34% 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 11,000 minutes out of 33,000, against a national NAS share of 21%.

Cancellations are rare at 0.60%, 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

6.8% 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 an hour and a half kind, which a normal layover absorbs.

The 589 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 79.9% on time across 2,329 flights, 3 points below 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 3 points of difference.

The sample behind these figures is 2,329 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. November runs 90.6% on time and August 74.4%, a swing of 16 points. If the dates move at all, move them out of August before you think about anything else. 2,310 completed flights over 12 months sit behind that.

Common questions

DSM to DEN questions

How often is DSM to DEN delayed?

About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.0% of the 2,329 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

Which airline is most reliable on DSM to DEN?

SkyWest Airlines leads at 90.0% on time across 936 flights. United Airlines is at the other end on 74.2%, a gap of 16 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 DSM to DEN?

The 5am–8am departure window is the strongest at 91.6% on time. The 5pm–8pm window is the weakest at 65.2%, 26 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 August delays on DSM to DEN?

August is the weakest month at 74.4% on time, compared with 90.6% in November. Across the year that is 16 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. DSM to DEN and DEN to DSM 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