Route Reliability

Route reliability

Denver (DEN) to Atlanta (ATL): which airline is most on time?

On-time arrivals, cancellations and long delays for every airline that reported nonstop flights from Denver, CO (DEN) to Atlanta, GA (ATL), September 2025 to August 2026.

Historical performance Official DOT data through August 2026 · Not live flight status

Denver, COAtlanta, GA

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Three-letter airport codes, nonstop U.S. domestic flights. One direction at a time.

Route at a glance · September 2025 to August 2026

DEN to ATL

Denver, CO to Atlanta, GA

On time
77.4%vs 75.6% U.S. average Better than average
Cancelled
0.9%vs 1.9% U.S. average Better than average
60+ min late
6.0%vs 8.1% U.S. average Better than average
Scheduled flights
5,603in 12 months4 airlines
Most reliable airline
Delta Air Lines84.5% on time · 2,807 flights

On time more often than the U.S. average, with fewer cancellations.

Compared with all U.S. flights, September 2025 to August 2026. “About average” means within 1.5 points for on time, 0.3 for cancelled and 1 for 60+ minutes late.

Airlines on this route

Ranked by on-time arrival

Airlines from DEN to ATL, September 2025 to August 2026. Rates are shares of all scheduled flights.
Airline On time Cancelled 60+ min late Avg delay when late Diverted Flights
1. Delta Air Lines Most reliable 84.5% 1.2% 4.1% 61 min 0.4% 2,807
2. United Airlines 76.7% 0.3% 6.9% 61 min 1.2% 923
3. Frontier Airlines 74.5% 0.9% 6.9% 62 min 0.4% 801
4. Southwest Airlines 61.7% 0.8% 9.7% 51 min 0.4% 1,072

On time = arrived within 15 minutes of schedule. Avg delay when late = average arrival delay of flights 15+ minutes late. "Most reliable" needs at least 300 flights in 12 months. Tap a heading to sort.

What this means

Delta Air Lines has the strongest record on this route.

  • Delta Air Lines had the best on-time record from Denver (DEN) to Atlanta (ATL): 84.5% of its 2,807 scheduled flights arrived within 15 minutes of schedule, compared with 61.7% for Southwest Airlines.
  • 0.9% of flights on this route were cancelled (about 1 in 111), 1.0 points lower than the U.S. average of 1.9%.
  • 6.0% of flights, about 1 in 17, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 58 min.
  • Overall, 77.4% of flights on this route arrived on time, 1.8 points higher than the U.S. average of 75.6%.
  • Over the last 3 years, November was the most reliable month on this route (85.0% on time) and July the least reliable (64.7%).
  • Cancellations peaked in January, when 2.6% of flights were cancelled.
  • Flights scheduled to depart 7 am to 8 am were the most punctual (92.3% on time); flights scheduled to depart 7 pm to 8 pm were the least (39.2%).
  • In the other direction, Atlanta (ATL) to Denver (DEN), 76.9% of flights were on time and 1.1% were cancelled. Compare airlines ATL to DEN.

Best and worst months to fly DEN to ATL

Jan 76.1%
Feb 81.2%
Mar 79.6%
Apr 77.4%
May 72.6%
Jun 72.4%
Jul 64.7%
Aug 74.5%
Sep 84.6%
Oct 83.7%
Nov 85.0%
Dec 81.2%
Share of scheduled flights on time 12-month average 77.4%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 76.1% 1,353
February 81.2% 1,269
March 79.6% 1,416
April 77.4% 1,415
May 72.6% 1,512
June 72.4% 1,563
July 64.7% 1,610
August 74.5% 1,512
September 84.6% 1,446
October 83.7% 1,502
November 85.0% 1,427
December 81.2% 1,480
Best and worst calendar month by airline, September 2023 to August 2026.
AirlineBest monthWorst month
Delta Air Lines September (90.8%) July (72.6%)
United Airlines November (87.1%) July (60.7%)
Frontier Airlines September (78.3%) July (62.9%)
Southwest Airlines November (81.8%) July (50.5%)

Month by month, last 12 months

Sep 84.9%
Oct 83.5%
Nov 88.7%
Dec 73.2%
Jan 81.4%
Feb 85.2%
Mar 75.2%
Apr 87.8%
May 73.9%
Jun 72.7%
Jul 60.8%
Aug 67.3%
Share of scheduled flights on time U.S. average 75.6%
All airlines combined, September 2025 to August 2026. Scale starts at zero.
Show as table
PeriodOn timeFlights
Sep 2025 84.9% 450
Oct 2025 83.5% 474
Nov 2025 88.7% 450
Dec 2025 73.2% 459
Jan 2026 81.4% 431
Feb 2026 85.2% 412
Mar 2026 75.2% 460
Apr 2026 87.8% 442
May 2026 73.9% 482
Jun 2026 72.7% 516
Jul 2026 60.8% 531
Aug 2026 67.3% 496

Best and worst departure times

<6a 91.9%
6a 88.7%
7a 92.3%
8a Insufficient sample
9a 77.3%
10a 77.6%
11a 73.7%
12p 85.9%
1p 78.4%
2p 73.6%
3p 71.9%
4p 75.3%
5p 66.7%
6p 40.5%
7p 39.2%
8p Insufficient sample
11p 61.2%
Share of scheduled flights on time
By scheduled local departure hour at DEN, September 2025 to August 2026. Hours with no scheduled flights are omitted. Scale starts at zero.
Show as table
PeriodOn timeFlights
Departing before 6 am 91.9% 542
Departing 6 am to 7 am 88.7% 335
Departing 7 am to 8 am 92.3% 402
Departing 8 am to 9 am Insufficient sample 45
Departing 9 am to 10 am 77.3% 273
Departing 10 am to 11 am 77.6% 934
Departing 11 am to noon 73.7% 209
Departing noon to 1 pm 85.9% 227
Departing 1 pm to 2 pm 78.4% 670
Departing 2 pm to 3 pm 73.6% 416
Departing 3 pm to 4 pm 71.9% 242
Departing 4 pm to 5 pm 75.3% 438
Departing 5 pm to 6 pm 66.7% 453
Departing 6 pm to 7 pm 40.5% 74
Departing 7 pm to 8 pm 39.2% 130
Departing 8 pm to 9 pm Insufficient sample 35
Departing 11 pm to midnight 61.2% 178
Woman at an airport window watching a plane take off
Photo: Depositphotos (licensed stock, illustrative only). Credits

Sources & data dates

Source
U.S. DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987-present)
Period
September 2025 to August 2026 (12 months); month-of-year patterns September 2023 to August 2026
Data through
August 2026
Processed
2026-11-03
Scope
Nonstop scheduled flights from Denver, CO (DEN) to Atlanta, GA (ATL), one direction. Airlines that report to the DOT only.
Method
Rates use all scheduled flights as the denominator; cancelled and diverted flights count as not on time. Figures based on fewer than 50 scheduled flights are suppressed. Full methodology.

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