Atlanta (ATL) to Denver (DEN): On-Time Performance
Data through May 2026
Atlanta (ATL) to Denver (DEN) effectively runs on two schedules. In October 2024, 89% of arrivals were on time; in June 2025 that fell to 61% — a 29-point seasonal swing. Across the full period the route averages 76% on-time against a national 78%. Morning departures also hold up better than evening ones (85% vs 64%), which matters most in the rough months.
- On-time
- 76%
- arrived <15 min late
- Avg delay
- 16 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 15
- last 12 months
- Duration
- 3h 22m
- scheduled
- Distance
- 1,199 mi
Best airline from ATL to DEN
4 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 85% | 13 min | 0.9% | 2,009 |
| Southwest Airlines | 77% | 14 min | 0.9% | 2,432 |
| Delta Air Lines | 76% | 14 min | 1.2% | 5,575 |
| Frontier Airlines | 64% | 32 min | 1.3% | 1,338 |
Monthly on-time trend
Best time to fly from ATL to DEN
Aim for departures around 6 a.m. (91% on-time); avoid 7 p.m. departures (53%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 18 min |
| Tuesday | 80% | 16 min |
| Wednesdaybest | 81% | 12 min |
| Thursday | 75% | 16 min |
| Friday | 75% | 16 min |
| Saturday | 76% | 15 min |
| Sunday | 72% | 20 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft34%
- Airline operations35%
- National airspace system25%
- Weather5%
Frequently asked questions
- How often are flights from ATL to DEN delayed?
- 24% of ATL–DEN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 16 minutes.
- Which airline is most reliable from ATL to DEN?
- United Airlines has the best on-time record on this route at 85%, based on 2,009 flights. 4 airlines flew ATL–DEN frequently enough to compare in this period.
- What is the best time of day to fly from ATL to DEN?
- Departures around 6 a.m. have the best record (91% on-time), while departures around 7 p.m. have the worst (53%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ATL to DEN?
- The scheduled ATL–DEN flight time averages 3h 22m over 1,199 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
- How often are ATL to DEN flights cancelled?
- 1.1% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from ATL to DEN?
- June 2025 was the roughest month in this dataset, with only 61% of arrivals on time. The best was October 2024 at 89%. If your dates are flexible, that 29-point gap is worth planning around.
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Based on 11,354 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.