Denver, CO · departure reliability

DEN

Denver International

Departures: 319,681
Period: September 2025 to August 2026
Carriers: 9
US rank: #2 by volume

Terminal building and aircraft stands at a US airport

Denver

Denver International lands a B+, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 319,681 flights, of which Delta Air Lines flew 11,497 at 83.1% on time.

Delta Air Lines is the most reliable of the nine carriers covered here at 83.1% on time across 11,497 flights.

On time

76.6%

Departures arriving under 15 minutes late at their destination

Avg delay

65 min

Across delayed flights only

Cancelled

0.78%

National rate is 1.89%

Best carrier

Delta

83.1% on time here

These figures cover 320,000 flights between September 2025 and August 2026. The median arrival is 5 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 airlines run best out of DEN

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 83.1% of the time; JetBlue Airways manages 65.7%. Sample sizes sit next to every figure, because a two-point gap across 1,258 flights means less than a ten-point one.

On-time performance by carrier departing DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	107,895	78.9%	65 min	0.41%	B+
Southwest Airlines	88,424	69.5%	54 min	0.72%	C+
SkyWest Airlines	75,223	80.4%	78 min	1.09%	B
Frontier Airlines	22,870	78.5%	68 min	0.77%	B+
Delta Air Lines	11,497	83.1%	75 min	1.37%	B
American Airlines	8,936	77.1%	105 min	1.97%	B
Alaska Airlines	2,879	78.1%	57 min	0.66%	B+
JetBlue Airways	1,258	65.7%	93 min	4.61%	C−
Allegiant Air	373	76.5%	94 min	0.54%	B+

JetBlue Airways cancels 4.6% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Route by route

Busiest routes out of DEN

Route-level records vary far more than the airport average. These are the 25 busiest departures from DEN, each with its own on-time rate against the airport-wide 76.6%.

Busiest routes from DEN by flight volume
Route	Flights	On time	Avg delay	Cancelled	Grade
DEN to PHX · Phoenix	9,069	75.6%	69 min	0.82%	B+
DEN to SLC · Salt Lake City	7,713	78.2%	61 min	0.35%	B+
DEN to LAX · Los Angeles	7,708	78.7%	63 min	0.53%	B+
DEN to LAS · Las Vegas	7,168	75.5%	64 min	0.64%	B+
DEN to SEA · Seattle	6,328	74.5%	58 min	0.60%	C+
DEN to SAN · San Diego	6,152	73.8%	56 min	0.83%	C+
DEN to ORD · Chicago	6,109	71.8%	88 min	1.11%	C
DEN to DFW · Dallas-Fort Worth	6,063	75.8%	83 min	1.80%	B
DEN to MSP · Minneapolis	5,828	78.5%	63 min	0.70%	B+
DEN to ATL · Atlanta	5,603	78.6%	58 min	0.93%	B+
DEN to SFO · San Francisco	5,488	63.2%	62 min	0.40%	D+
DEN to AUS · Austin	5,486	76.2%	62 min	0.55%	B+
DEN to COS · Colorado Springs	4,989	76.5%	68 min	1.26%	B
DEN to IAH · Houston	4,728	79.6%	62 min	0.30%	B+
DEN to LGA · New York	4,664	71.3%	70 min	2.92%	C
DEN to MCO · Orlando	4,528	77.8%	62 min	0.68%	B+
DEN to MCI · Kansas City	4,364	76.5%	62 min	0.41%	B+
DEN to PDX · Portland	4,280	74.8%	55 min	0.33%	C+
DEN to SMF · Sacramento	3,853	73.2%	56 min	0.29%	C+
DEN to BOS · Boston	3,851	69.6%	73 min	1.45%	C
DEN to SNA · Santa Ana	3,710	80.6%	45 min	0.16%	B+
DEN to STL · St. Louis	3,699	77.7%	61 min	0.49%	B+
DEN to BNA · Nashville	3,617	74.9%	56 min	0.53%	C+
DEN to IAD · Washington	3,385	81.8%	60 min	0.59%	B+
DEN to EWR · Newark	3,344	78.8%	83 min	1.53%	B

Departure window

The best time of day to leave DEN

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against 17 points between the best and worst carrier.

5am–8am25,458 flights90.9%
8am–11am65,126 flights85.5%
11am–2pm70,182 flights79.9%
2pm–5pm48,512 flights73.2%
5pm–8pm69,495 flights66.5%
8pm–5am40,908 flights69.2%

Scale runs 60% to 95%.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.9% of the time, against 66.5% for the evening window. That is 24 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 70,182 flights scheduled in it.

Explore

Filter DEN departures by airline, time, month and day

Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.

On departures from Denver (DEN), the best departure window is 5am–8am at 90.9% on time and the worst is 5pm–8pm at 66.5%, a wide gap of 24.4 points. All US flights leaving 5am–8am ran 89.3%.

5–8am90.9%
8–11am85.5%
11am–2pm79.9%
2–5pm73.2%
5–8pm66.5%
8pm–5am69.2%

best all US flightsScale 60% to 95%.

Across the year

When DEN runs late

DEN's year swings by 18 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, June worst

August is the worst month at 67.1% on time, 18 points below November, the best at 84.7%. 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 29,503 flights.

Across the week, Tuesday is the strongest day at 80.9% on time and Sunday the weakest at 74.4%, a spread of 7 points.

DEN month by month

From Europe

Transatlantic routes into DEN

7 European airports send scheduled passenger flights to DEN, 6,018 flights a year in both directions by the DOT's international count. The DOT keeps no delay record for international flights; the UK routes carry the CAA's departure punctuality, and every route sets its departure airport's EUROCONTROL figures beside DEN's own record above.

Every Europe-to-US route

Delay causes

Why DEN gets delayed

Late-arriving aircraft accounts for 44% of the 4.82 million delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
44%
Carrier
32%
National Airspace System
19%
Extreme weather
4%
Security
0%

44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4.82 million reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 4,821,317 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.9% on time here.

Cancellations are rare at 0.78%, below the national 1.89% 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.

7.8% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

319,681 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.

What to do with this

Flying out of DEN

Put together: the calendar is the biggest lever here, not the carrier or the hour. November runs 84.7% on time and August 67.1%, a swing of 18 points. If the dates move at all, move them out of August before you think about anything else. 316,245 completed flights over 12 months sit behind that.

Common questions

DEN delay questions

How often is Denver (DEN) delayed?

About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.4% of the 319,681 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on Denver (DEN)?

Delta Air Lines leads at 83.1% on time across 11,497 flights. JetBlue Airways is at the other end on 65.7%, 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 Denver (DEN)?

The 5am–8am departure window is the strongest at 90.9% on time. The 5pm–8pm window is the weakest at 66.5%, 24 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 Denver (DEN)?

August is the weakest month at 67.1% on time, compared with 84.7% in November. Across the year that is 18 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

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<iframe src="https://delayatlas.com/embed/airport/den" width="320" height="132" style="border:0;max-width:100%" loading="lazy" title="DEN airport on-time record"></iframe>
<p style="font:12px/1.4 sans-serif;margin:4px 0 0">DEN airport delay statistics from <a href="https://delayatlas.com/airports/den">DelayAtlas</a></p>

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.