Airport month record

DENJUN

Denver International in June 2026

Departures: 28,634
Month: June 2026
National, same month: 74.3%
Carriers: 9

Historical statistics for June 2026, not live status or a forecast for this year’s June. For today’s conditions at DEN, see live FAA status.

DEN in June draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 28,634 flights, of which Delta Air Lines flew 1,049 at 81.2% on time.

Delta Air Lines is the most reliable of the six carriers covered here at 81.2% on time across 1,049 flights.

On time

67.1%

Arrivals under 15 minutes late, of 28,420 completed departures

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

0.41%

Nationally in June: 1.65%

Whole year

76.3%

DEN across all twelve months

These figures cover 28,634 departures from Denver International in June 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

June next to DEN's other months

Against DEN's own year, June ran 9 points worse than the twelve-month rate of 76.3%, which makes it number eleven of twelve months, best first. Cancellations were unusually low for DEN in June, at 0.41% against 0.79% across the year.

DEN month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	29,433	63.0%	77 min	1.48%	D
August 2025	28,084	70.1%	69 min	0.73%	C+
September 2025	26,548	79.4%	54 min	0.12%	B+
October 2025	27,763	80.8%	52 min	0.13%	B+
November 2025	25,280	84.7%	62 min	1.44%	B
December 2025	26,026	74.3%	68 min	0.64%	C+
January 2026	24,484	82.3%	60 min	1.69%	B
February 2026	23,046	82.4%	69 min	0.88%	B+
March 2026	27,089	76.8%	72 min	1.50%	B
April 2026	25,345	82.5%	56 min	0.27%	B+
May 2026	27,406	76.4%	58 min	0.28%	B+
June 2026 (this page)	28,634	67.1%	64 min	0.41%	C+

Departure window

The best time of day to leave DEN in June

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 points, against 27 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am2,748 flights88.3%
8am–11am5,537 flights82.0%
11am–2pm5,926 flights71.1%
2pm–5pm4,463 flights64.4%
5pm–8pm6,156 flights50.0%
8pm–5am3,804 flights54.7%

Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 50.0% on time, against 88.3% 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 5pm–8pm window is the busiest, with 6,156 flights scheduled in it.

Across the week, Tuesday is the strongest day at 73.1% on time and Sunday the weakest at 59.0%. 14 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at DEN in June

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 81.2% of the time; Southwest Airlines manages 54.3%. Sample sizes sit next to every figure, because a two-point gap across 8,029 flights means less than a ten-point one.

Carriers at DEN in June 2026
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	9,694	70.6%	64 min	0.11%	C+
Southwest Airlines	8,029	54.3%	55 min	0.46%	F+
SkyWest Airlines	6,396	72.8%	73 min	0.20%	C+
Frontier Airlines	2,150	74.6%	71 min	0.70%	C+
Delta Air Lines	1,049	81.2%	71 min	0.86%	B+
American Airlines	805	66.2%	99 min	2.73%	C
Alaska Airlinesthin sample	311	76.4%	66 min	1.61%	B
JetBlue Airwaysthin sample	137	59.7%	86 min	2.19%	D
Allegiant Airthin sample	62	72.1%	81 min	1.61%	C

The spread between Delta and Southwest is 27 points, wide enough that it should decide the booking. On a hundred trips that is 27 more arrivals inside the on-time window.

Route by route

Busiest routes out of DEN in June

Routes from DEN in June 2026
Route	Flights	On time	Avg delay	Cancelled	Grade
DEN to PHX · Phoenix	683	66.1%	67 min	0.73%	C+
DEN to SLC · Salt Lake City	657	68.8%	56 min	0.15%	C+
DEN to LAX · Los Angeles	654	66.5%	65 min	0.46%	C+
DEN to SEA · Seattle	634	69.6%	62 min	1.26%	C
DEN to LAS · Las Vegas	593	65.4%	66 min	0.84%	C+
DEN to MSP · Minneapolis	548	70.5%	63 min	0.55%	C+
DEN to DFW · Dallas-Fort Worth	539	63.1%	88 min	2.97%	D
DEN to ORD · Chicago	537	66.5%	97 min	1.12%	C
DEN to SAN · San Diego	525	65.0%	54 min	0.38%	C+
DEN to ATL · Atlanta	516	73.2%	59 min	0.19%	C+
DEN to AUS · Austin	502	64.5%	57 min	0.40%	D+
DEN to SFO · San Francisco	494	39.4%	63 min	0.40%	F+
DEN to COS · Colorado Springs	436	68.9%	64 min	0.23%	C+
DEN to PDX · Portland	435	60.4%	51 min	0.23%	D+
DEN to IAH · Houston	431	68.6%	59 min	0.00%	C+
DEN to MCO · Orlando	420	69.3%	66 min	0.24%	C+
DEN to MCI · Kansas City	419	68.3%	64 min	0.48%	C+
DEN to LGA · New York	394	61.3%	62 min	1.02%	D
DEN to SMF · Sacramento	376	59.0%	55 min	0.00%	D+
DEN to BOS · Boston	374	66.4%	70 min	0.27%	C+
DEN to STL · St. Louisthin sample	358	69.3%	53 min	1.40%	C
DEN to BNA · Nashvillethin sample	340	63.7%	58 min	0.29%	D+
DEN to SNA · Santa Anathin sample	327	66.7%	45 min	0.00%	C+
DEN to OMA · Omahathin sample	324	65.1%	60 min	0.00%	C+
DEN to PHL · Philadelphiathin sample	316	67.5%	100 min	0.63%	C+

Delay causes

What held DEN up in June

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 597,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
45%
Carrier
30%
National Airspace System
20%
Extreme weather
6%
Security
0%

45% 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 597,000 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 596,740 reported delay minutes.

Cancellations are rare at 0.41%, below the national 1.65% 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.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.3% of arrivals land a full hour or more behind schedule, against 9.7% 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.

What to do with this

Flying from DEN in June

For a June trip through DEN: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 88.3% on time, and with 11.3% of arrivals an hour or more late, a connection here deserves more slack than the same trip in November would.

Denver International (DEN), the whole year
DEN in July63.0%
DEN in August70.1%
DEN in September79.4%
DEN in October80.8%
DEN in November84.7%
DEN in December74.3%
DEN in January82.3%
DEN in February82.4%
DEN in March76.8%
DEN in April82.5%
DEN in May76.4%

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.

Key figures