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DelayAtlas

Airport month record

ATLAUG

Hartsfield-Jackson Atlanta International in August 2025

Departures
27,353
Month
August 2025
National, same month
77.4%
Carriers
12
B+GRADE

Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at ATL, see live FAA status.

ATL in August lands a B+, about a point better than the national rate of 77.4%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 27,353 flights, of which Delta Air Lines flew 20,844 at 80.2% on time.

Delta Air Lines is the most reliable of the seven carriers covered here at 80.2% on time across 20,844 flights.

Key figures

On time

78.4%

Arrivals under 15 minutes late, of 27,042 completed departures

Avg delay

67 min

Across delayed arrivals only, not all flights

Cancelled

0.85%

Nationally in August: 1.08%

Whole year

78.4%

ATL across all twelve months

These figures cover 27,353 departures from Hartsfield-Jackson Atlanta International in August 2025. 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

August next to ATL's other months

Against ATL's own year, August ran level with the twelve-month rate of 78.4%, which makes it number seven of twelve months, best first. Cancellations were unusually low for ATL in August, at 0.85% against 1.73% across the year. Either side of it, July ran 68.8% on time and September 86.5%, so this month sits in line with its neighbours.

ATL month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 202528,55168.8%75 min1.59%C
August 2025 (this page)27,35378.4%67 min0.85%B+
September 202525,83986.5%54 min0.07%A+
October 202527,55681.6%57 min0.20%B+
November 202525,88880.3%66 min2.45%B
December 202525,76473.2%69 min2.38%C
January 202624,59578.3%61 min5.00%B−
February 202623,02480.3%56 min1.49%B
March 202626,66974.8%71 min3.46%C−
April 202626,60782.1%57 min1.00%B
May 202627,53577.2%61 min1.18%B
June 202626,96180.1%70 min1.38%B

Departure window

The best time of day to leave ATL in August

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 19 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,774 flights90.3%
  • 8am–11am5,725 flights87.0%
  • 11am–2pm4,556 flights85.2%
  • 2pm–5pm5,308 flights75.3%
  • 5pm–8pm4,164 flights67.8%
  • 8pm–5am5,826 flights71.2%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.3% of the time, against 67.8% for the evening window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 5,826 flights scheduled in it.

Across the week, Wednesday is the strongest day at 81.7% on time and Friday the weakest at 71.9%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week81.2Mon79.7Tue81.7Wed76.2Thu71.9Fri81.1Sat78.5Sun
Monday: 81.2 percent on time. Tuesday: 79.7 percent on time. Wednesday: 81.7 percent on time. Thursday: 76.2 percent on time. Friday: 71.9 percent on time. Saturday: 81.1 percent on time. Sunday: 78.5 percent on time

Carrier by carrier

Which airlines ran best at ATL in August

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 80.2% of the time; Frontier Airlines manages 61.2%. Sample sizes sit next to every figure, because a two-point gap across 1,461 flights means less than a ten-point one.

Carriers at ATL in August 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines20,84480.2%60 min0.74%B+
Southwest Airlines1,62776.1%61 min0.43%B+
Frontier Airlines1,46161.2%82 min2.46%D
SkyWest Airlines76273.7%110 min0.13%C+
Spirit Airlines62776.9%69 min0.16%B+
United Airlines62379.3%77 min1.12%B
American Airlines60871.5%109 min2.14%C
PSA Airlinesthin sample27875.3%131 min2.52%B
JetBlue Airwaysthin sample16076.7%65 min0.62%B+
Alaska Airlinesthin sample15272.0%64 min0.66%C+
Republic Airwaysthin sample13580.0%91 min2.96%B
Envoy Airthin sample7682.9%65 min0.00%B+

The spread between Delta and Frontier is 19 points, wide enough that it should decide the booking. On a hundred trips that is 19 more arrivals inside the on-time window.

Route by route

Busiest routes out of ATL in August

Routes from ATL in August 2025
RouteFlightsOn timeAvg delayCancelledGrade
ATL to MCO · Orlando63464.6%82 min0.16%D+
ATL to LGA · New York60778.3%76 min1.32%B
ATL to DCA · Washington58373.9%74 min1.54%C
ATL to ORD · Chicago57378.5%87 min1.75%B
ATL to DFW · Dallas-Fort Worth55272.7%101 min1.99%C
ATL to EWR · Newark53771.8%73 min1.49%C
ATL to PHL · Philadelphia50674.9%62 min2.17%C
ATL to MIA · Miami49867.7%76 min0.80%C+
ATL to DEN · Denver49571.3%63 min0.81%C+
ATL to FLL · Fort Lauderdale49571.5%55 min0.20%C+
ATL to BWI · Baltimore49374.5%71 min1.62%C
ATL to LAX · Los Angeles48278.6%58 min0.83%B+
ATL to TPA · Tampa47269.2%59 min0.21%C+
ATL to DTW · Detroit44778.9%65 min0.45%B+
ATL to AUS · Austin40770.8%47 min1.47%C
ATL to CLT · Charlotte40577.9%94 min0.49%B+
ATL to LAS · Las Vegas40477.2%54 min0.99%B+
ATL to BOS · Boston40382.3%57 min0.25%B+
ATL to RDU · Raleigh40279.9%51 min0.75%B+
ATL to IAH · Houston38072.9%65 min1.05%C
ATL to JFK · New York37678.8%76 min0.80%B+
ATL to BNA · Nashville36586.4%50 min1.10%A
ATL to IAD · Washingtonthin sample34474.2%106 min0.58%C+
ATL to MSY · New Orleansthin sample33277.8%64 min0.90%B+
ATL to STL · St. Louisthin sample33183.0%54 min1.51%B

Delay causes

What held ATL up in August

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 392,000 reported delay minutes.

  • Carrier
    42%
  • Late-arriving aircraft
    30%
  • National Airspace System
    19%
  • Extreme weather
    8%
  • Security
    0%

The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 165,000 of the 392,000 delay minutes reported here. The split is drawn from 392,204 reported delay minutes.

Cancellations are rare at 0.85%, below the national 1.08% 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.

7.8% of arrivals land an hour or more late, close to the national 8.2%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

What to do with this

Flying from ATL in August

For a August trip through ATL: expect 78.4% on time and 0.85% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.

Related

Where to go next

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.