Best time to fly out of Denver (DEN)

The early-flight folk wisdom holds up at Denver: departures in the 6–8am band left on time 90.9% of the time, against 63.3% in the 6–8pm band. These are historical odds, not forecasts. The records say what happened on this schedule over three years; they know nothing about tomorrow’s thunderstorm.

Data through June 2026 · Bureau of Transportation Statistics

On-time rate by hour and day

On this page, “on time” means a departure that pushed back less than 15 minutes behind its scheduled time — the Bureau of Transportation Statistics definition, and the one airlines are held to.

Share of departures that left on time, by hour band and day of week.
Departure time MonTueWedThuFriSatSun
Before 6am 87 87 91 91 88 87 88
6–8am 90 92 93 91 90 90 90
8–10am 85 87 89 87 84 86 85
10am–12pm 81 83 83 81 79 80 80
12–2pm 77 80 81 77 76 79 77
2–4pm 69 74 75 70 68 72 69
4–6pm 70 72 72 68 68 71 67
6–8pm 62 68 67 61 62 63 60
8–10pm 65 71 71 63 64 68 61
10pm–12am 65 73 76 63 65 71 62
fewer left on time more left on time

The steadiest stretch at DEN was 6–8am — 90.9% of departures left on time across 77,006 flights. The weakest was 6–8pm at 63.3%. 6–8am departures from DEN left on time 90.9% of the time across 77,006 flights; 6–8pm departures, 63.3% across 113,532. That is a gap of 27.6 points, and it is the whole case for the early flight.

The year at DEN

July was the hard month at DEN: 65.4% of departures left on time, across 83,518 flights. November was the easy one at 82.8%. Each month pools three years of that month, so a single bad week does not decide it.

Share of departures that left on time, by calendar month. Best month in green, worst in amber. The hairline sits at the overall rate, 75.8%.
Departure on-time share at DEN by calendar month
Month Share departures that left on time Flights
January 76.7% 72,577
February 78.1% 67,621
March 77.8% 78,720
April 78.3% 75,282
May 72.1% 80,668
June 67.9% 84,394
July 65.4% 83,518
August 71.8% 81,726
September 80.5% 77,432
October 81.4% 80,235
November 82.8% 74,438
December 78.5% 76,985

Airlines at DEN

Every airline with at least 100 departures from DEN, busiest first. These are that airline’s departures from this airport only — its record across the country sits on its own page.

Airline Left on time Typical delay Cancelled Departures
United Airlines 79.6% 68 min 0.7% 310,528
Southwest Airlines 67.3% 50 min 0.7% 281,472
SkyWest Airlines 81.3% 82 min 1.2% 195,665
Frontier Airlines 74.3% 67 min 1.1% 70,373
Delta Air Lines 82.1% 77 min 0.9% 35,807
American Airlines 77.7% 99 min 1.7% 25,986
Alaska Airlines 77.7% 59 min 1% 6,999
JetBlue Airways 64.5% 98 min 2.1% 3,998
Allegiant Air 70.5% 103 min 1.3% 1,341
Spirit Airlines 66.9% 69 min 1.2% 771
Envoy Air 71.8% 81 min 0.5% 656

Spirit Airlines (through May 2026) stopped filing before June 2026. Its row covers a shorter run of months than the rest of the table, so its figure is not set against the others anywhere on this page.

What delays out of DEN were put down to

Airlines file a reason with every arrival running 15 minutes late or more. Across 219,457 flights that departed DEN and ran 15 minutes late or more, the delay minutes break down with 43.9% put down to late-arriving aircraft and 33.3% to airline operations.

Late-arriving aircraft 43.9% Airline operations 33.3% Air traffic & airport volume 18.1% Severe weather 4.6% Security 0.1%
  • Late-arriving aircraft 43.9%
  • Airline operations 33.3%
  • Air traffic & airport volume 18.1%
  • Severe weather 4.6%
  • Security 0.1%

Late-arriving aircraft is the knock-on category: the plane came in late, so it went out late again. It is why a 7am problem in Newark is still a problem in Denver at dinnertime, and why it is usually the biggest slice on the bar.

If you are connecting through DEN

Of 933,527 scheduled arrivals into DEN, 78.3% reached the gate less than 15 minutes behind schedule. Of the 189,705 arrivals that ran late, 53.5% were no more than 45 minutes behind — which is the difference between a tight connection and a new boarding pass.

Work out a specific layover — pick the airport and the minutes you have, and the tool reads the same arrival records back as a share.

Busiest routes out of DEN

Ranked by flights, with the share that arrived on time at the far end. Where a route carries enough flights for a page of its own the chip goes there; otherwise it goes to the destination airport.

DEN in one number

Denver (DEN)

Rank 2 of 363 US airports by departures. Steadiest stretch of the day: 6–8am. Hardest month: July.

July 2023–June 2026 · 925,064 departures flown

75.8% of departures left on time

Questions about DEN

What is the best time of day to fly out of Denver?
6–8am. Departures in that band left on time 90.9% of the time across 77,006 flights, July 2023 through June 2026 — the best of the ten bands in the day. The 6–8pm band was the weakest at 63.3%.
Is the early flight out of DEN really more reliable?
6–8am departures from DEN left on time 90.9% of the time across 77,006 flights; 6–8pm departures, 63.3% across 113,532. That is a gap of 27.6 points, and it is the whole case for the early flight.
What is the worst month to fly out of DEN?
July: 65.4% of the departures that flew left on time, with 83,518 scheduled. November was the other end of the year at 82.8%. Each figure pools three years of that calendar month.
Which airline is most on time at DEN?
Delta Air Lines — 82.1% of its 35,807 departures from DEN left on time. JetBlue Airways sat at the other end at 64.5% over 3,998 flights. Only airlines with at least 100 departures here are ranked. Airlines that stopped filing before June 2026 are left out of the ranking — their figures cover a shorter run of months than the rest of the table.
How often are flights cancelled at DEN?
0.9% of scheduled departures were cancelled over July 2023 through June 2026. Cancellations are counted against everything scheduled, not against everything that flew — a rate that looks small still adds up to real people in a rebooking line.