Route on-time record

ATL to DEN: most on-time flights and the best time to fly

Atlanta (Hartsfield Jackson Atlanta International Airport) to Denver (Denver International Airport). 5,582 nonstop flights in Jun 2025 to May 2026, 76% arrived within 15 minutes and 1.1% were cancelled. The most reliable flight number was United 1327 at 11:10 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

ATL → DEN

Atlanta to Denver: 5,582 nonstop flights a year

On time (12 months)

76%

Cancelled

1.1%

avg delay 16 min

Best time to leave

Before 9 AM

86% on time vs 61% 6 to 9 PM

Most reliable airline

United

84% chance on time

Check ATL to DEN fares

Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

#1 · United 1327
11:10 AM → 12:28 PM3h 18m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
On time (history)
90%
Cancelled
0.0%
Avg arrival delay
10 min
- Arrived on time 90% of the time (195 flights, Jun 2025 to May 2026).
- Never cancelled in 195 scheduled flights.
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- 63% of its delay minutes came from the plane arriving late from an earlier flight.
Moderate track record · 195 flights
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#2 · United 1378
7:30 AM → 8:51 AM3h 21m nonstop
Local times, typical schedule. Last flown 2026-05-30.
91%
chance on time
On time (history)
100%
Cancelled
0.0%
Avg arrival delay
1 min
- Arrived on time 100% of the time (9 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 86% on time; 6 to 9 PM: 61%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Short track record (9 flights), so its score leans on the airline's record at this hour.
Limited track record · 9 flights
Find United 1378 fares Opens this date on Aviasales
#3 · Delta 785
9:55 AM → 11:18 AM3h 23m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
100%
Cancelled
0.0%
Avg arrival delay
0 min
- Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Short track record (11 flights), so its score leans on the airline's record at this hour.
Limited track record · 11 flights
Find Delta 785 fares Opens this date on Aviasales
#4 · United 340
9:00 AM → 10:32 AM3h 32m nonstop
Local times, typical schedule. Last flown 2026-05-20.
86%
chance on time
On time (history)
87%
Cancelled
1.4%
Avg arrival delay
10 min
- Arrived on time 87% of the time (288 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 288 flights
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#5 · Delta 957
12:44 PM → 2:04 PM3h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
86%
Cancelled
0.0%
Avg arrival delay
8 min
- Arrived on time 86% of the time (84 flights, Jun 2025 to May 2026).
- Never cancelled in 85 scheduled flights.
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Moderate track record · 84 flights
Find Delta 957 fares Opens this date on Aviasales
#6 · Southwest 2647
6:20 AM → 7:40 AM3h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1228; its record covers all of them.
86%
chance on time
On time (history)
90%
Cancelled
0.0%
Avg arrival delay
9 min
- Arrived on time 90% of the time (88 flights, Jun 2025 to May 2026).
- Never cancelled in 88 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 86% on time; 6 to 9 PM: 61%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 88 flights
Find Southwest 2647 fares Opens this date on Aviasales
#7 · Delta 706
12:15 PM → 1:34 PM3h 19m nonstop
Local times, typical schedule. Last flown 2026-05-31.
84%
chance on time
On time (history)
85%
Cancelled
0.0%
Avg arrival delay
9 min
- Arrived on time 85% of the time (358 flights, Jun 2025 to May 2026).
- Never cancelled in 358 scheduled flights.
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 358 flights
Find Delta 706 fares Opens this date on Aviasales
#8 · Delta 346
8:05 AM → 9:26 AM3h 21m nonstop
Local times, typical schedule. Last flown 2026-05-06.
84%
chance on time
On time (history)
86%
Cancelled
3.7%
Avg arrival delay
6 min
- Arrived on time 86% of the time (103 flights, Jun 2025 to May 2026).
- Cancelled 3.7% of the time (4 of 107).
- Leaves in this route's most on-time window (Before 9 AM: 86% on time; 6 to 9 PM: 61%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 103 flights
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#9 · Delta 995
10:44 AM → 12:04 PM3h 20m nonstop
Local times, typical schedule. Last flown 2026-05-06.
81%
chance on time
On time (history)
83%
Cancelled
2.4%
Avg arrival delay
7 min
- Arrived on time 83% of the time (200 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 200 flights
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#10 · Delta 840
1:53 PM → 3:12 PM3h 19m nonstop
Local times, typical schedule. Last flown 2026-05-31.
81%
chance on time
On time (history)
85%
Cancelled
0.0%
Avg arrival delay
11 min
- Arrived on time 85% of the time (85 flights, Jun 2025 to May 2026).
- Never cancelled in 85 scheduled flights.
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Moderate track record · 85 flights
Find Delta 840 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

United Airlines84%
992 flights · 85% on time as flown · 0.5% cancel
Delta Air Lines75%
2,803 flights · 76% on time as flown · 1.2% cancel
Southwest Airlines72%
1,083 flights · 72% on time as flown · 1.3% cancel
Frontier Airlines68%
704 flights · 68% on time as flown · 1.2% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

Before 9 AM86%
1,081 flights · avg delay 9 min
9 AM to noon86%
1,064 flights · avg delay 9 min
Noon to 3 PM80%
1,044 flights · avg delay 11 min
3 to 6 PM68%
813 flights · avg delay 20 min
6 to 9 PM61%
1,107 flights · avg delay 29 min
After 9 PM71%
473 flights · avg delay 19 min

Best day: Wednesday (81%). Worst: Sunday (74%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

What delays this route

Airline (crew, maintenance, boarding)34%
Late-arriving aircraft31%
Air traffic control and airport volume29%
Severe weather6%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

ATL to DEN questions

What time of day is best to fly ATL to DEN?: Before 9 AM: 86% of flights arrived on time, against 61% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from ATL to DEN?: United, with a season-adjusted 84% chance of operating and arriving on time over 992 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on ATL to DEN?: June (66% on time); the best was November (86%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?: No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

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