Airport month record

ATLSEP

Hartsfield-Jackson Atlanta International in September 2025

Departures: 25,839
Month: September 2025
National, same month: 83.4%
Carriers: 12

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

ATL in September earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 3 points better than the national rate of 83.4%. When something does go wrong the average delay runs about 55 minutes. That rests on 25,839 flights, of which SkyWest Airlines flew 610 at 89.3% on time.

SkyWest Airlines is the most reliable of the seven carriers covered here at 89.3% on time across 610 flights.

On time

86.5%

Arrivals under 15 minutes late, of 25,765 completed departures

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.07%

Nationally in September: 0.51%

Whole year

78.4%

ATL across all twelve months

These figures cover 25,839 departures from Hartsfield-Jackson Atlanta International in September 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

September next to ATL's other months

Against ATL's own year, September ran 8 points better than the twelve-month rate of 78.4%, which makes it the best of the twelve months in the data. Cancellations were unusually low for ATL in September, at 0.07% against 1.73% across the year. Either side of it, August ran 78.4% on time and October 81.6%, so a trip moved by a few weeks would have landed in a worse stretch.

ATL month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	28,551	68.8%	75 min	1.59%	C
August 2025	27,353	78.4%	67 min	0.85%	B+
September 2025 (this page)	25,839	86.5%	54 min	0.07%	A+
October 2025	27,556	81.6%	57 min	0.20%	B+
November 2025	25,888	80.3%	66 min	2.45%	B
December 2025	25,764	73.2%	69 min	2.38%	C
January 2026	24,595	78.3%	61 min	5.00%	B−
February 2026	23,024	80.3%	56 min	1.49%	B
March 2026	26,669	74.8%	71 min	3.46%	C−
April 2026	26,607	82.1%	57 min	1.00%	B
May 2026	27,535	77.2%	61 min	1.18%	B
June 2026	26,961	80.1%	70 min	1.38%	B

Departure window

The best time of day to leave ATL in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,627 flights91.3%
8am–11am5,403 flights91.7%
11am–2pm4,404 flights89.6%
2pm–5pm5,141 flights83.0%
5pm–8pm3,940 flights79.7%
8pm–5am5,324 flights85.7%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 91.7% of the time, against 79.7% for the evening window. That is 12 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 5,403 flights scheduled in it.

Across the week, Tuesday is the strongest day at 90.6% on time and Thursday the weakest at 83.3%. 7 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at ATL in September

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.3% of the time; Frontier Airlines manages 78.4%. Sample sizes sit next to every figure, because a two-point gap across 1,369 flights means less than a ten-point one.

Carriers at ATL in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	19,675	87.2%	49 min	0.00%	A+
Southwest Airlines	1,594	85.9%	44 min	0.00%	A+
Frontier Airlines	1,369	78.4%	68 min	0.00%	B+
United Airlines	637	87.5%	69 min	0.47%	A+
SkyWest Airlines	610	89.3%	95 min	0.33%	A+
American Airlines	536	84.5%	75 min	1.31%	B
Spirit Airlines	529	88.8%	94 min	0.19%	A+
Republic Airwaysthin sample	283	84.8%	89 min	0.35%	B+
PSA Airlinesthin sample	262	86.9%	61 min	1.15%	A
JetBlue Airwaysthin sample	168	71.1%	114 min	1.19%	C
Alaska Airlinesthin sample	141	89.3%	52 min	0.00%	A+
Envoy Airthin sample	35	74.3%	50 min	0.00%	C+

SkyWest leads Frontier by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of ATL in September

Routes from ATL in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
ATL to LGA · New York	744	86.8%	71 min	0.13%	A+
ATL to DCA · Washington	592	80.0%	44 min	0.34%	B+
ATL to MCO · Orlando	563	79.2%	51 min	0.00%	B+
ATL to DFW · Dallas-Fort Worth	544	81.7%	69 min	1.10%	B
ATL to ORD · Chicago	541	84.4%	56 min	0.18%	B+
ATL to EWR · Newark	520	83.4%	88 min	0.19%	B+
ATL to BWI · Baltimore	465	88.1%	45 min	0.00%	A+
ATL to LAX · Los Angeles	455	82.6%	72 min	0.00%	B+
ATL to FLL · Fort Lauderdale	453	84.9%	56 min	0.00%	B+
ATL to DEN · Denver	450	81.5%	45 min	0.22%	B+
ATL to PHL · Philadelphia	436	84.3%	49 min	0.46%	B+
ATL to TPA · Tampa	433	82.2%	53 min	0.00%	B+
ATL to DTW · Detroit	421	87.9%	45 min	0.24%	A+
ATL to MIA · Miami	421	80.1%	49 min	0.00%	B+
ATL to RDU · Raleigh	401	91.3%	44 min	0.00%	A+
ATL to BOS · Boston	399	69.3%	69 min	0.25%	C+
ATL to LAS · Las Vegas	389	80.5%	53 min	0.00%	B+
ATL to JFK · New York	387	84.7%	101 min	0.26%	B+
ATL to AUS · Austin	385	86.8%	52 min	0.00%	A+
ATL to IAH · Houston	384	86.2%	58 min	0.26%	A+
ATL to CLT · Charlotte	370	87.3%	56 min	0.00%	A+
ATL to BNA · Nashvillethin sample	343	88.6%	36 min	0.00%	A+
ATL to STL · St. Louisthin sample	317	92.4%	49 min	0.00%	A+
ATL to IAD · Washingtonthin sample	315	82.9%	78 min	0.00%	B+
ATL to DAL · Dallasthin sample	305	86.8%	62 min	0.00%	A+

Delay causes

What held ATL up in September

One category carries most of the weight here. Carrier accounts for 51% of the 189,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
51%
National Airspace System
24%
Late-arriving aircraft
23%
Extreme weather
1%
Security
0%

The largest share of delay minutes, 51%, 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 97,000 of the 189,000 delay minutes reported here. The split is drawn from 188,545 reported delay minutes.

Cancellations are rare at 0.07%, below the national 0.51% 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.

Badly late arrivals are rare here: only 3.4% land an hour or more behind schedule, against 5.4% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

What to do with this

Flying from ATL in September

For a September trip through ATL: this is one of the better months to be flying from here, 86.5% on time with 0.07% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

Hartsfield-Jackson Atlanta International (ATL), the whole year
ATL in July68.8%
ATL in August78.4%
ATL in October81.6%
ATL in November80.3%
ATL in December73.2%
ATL in January78.3%
ATL in February80.3%
ATL in March74.8%
ATL in April82.1%
ATL in May77.2%
ATL in June80.1%

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.

Key figures