Airport month record
ATLMAY
Hartsfield-Jackson Atlanta International in May 2026
- Departures
- 27,535
- Month
- May 2026
- National, same month
- 78.6%
- Carriers
- 11
Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at ATL, see live FAA status.
ATL in May lands a B, about a point worse than the national rate of 78.6%. Roughly one flight in four 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 27,535 flights, of which United Airlines flew 690 at 80.8% on time.
United Airlines is the most reliable of the six carriers covered here at 80.8% on time across 690 flights.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 27,138 completed departures
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
1.18%
Nationally in May: 0.92%
Whole year
78.4%
ATL across all twelve months
These figures cover 27,535 departures from Hartsfield-Jackson Atlanta International in May 2026. 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
May next to ATL's other months
Against ATL's own year, May ran about a point worse than the twelve-month rate of 78.4%, which makes it number nine of twelve months, best first. Either side of it, April ran 82.1% on time and June 80.1%, so a trip moved by a few weeks would have landed in a better stretch.
| 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 | 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 (this page) | 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 May
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 14 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,904 flights90.0%
- 8am–11am5,581 flights87.4%
- 11am–2pm4,517 flights84.4%
- 2pm–5pm5,162 flights74.4%
- 5pm–8pm4,447 flights64.0%
- 8pm–5am5,924 flights70.3%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.0% on time, against 90.0% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 5,924 flights scheduled in it.
Across the week, Saturday is the strongest day at 81.6% on time and Friday the weakest at 74.0%. 8 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at ATL in May
The choice of carrier is not cosmetic here. United Airlines arrives on time 80.8% of the time; Southwest Airlines manages 66.4%. Sample sizes sit next to every figure, because a two-point gap across 1,330 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 21,328 | 79.0% | 54 min | 1.28% | B |
| Frontier Airlines | 2,018 | 67.1% | 76 min | 0.59% | C+ |
| Southwest Airlines | 1,330 | 66.4% | 61 min | 0.38% | C+ |
| United Airlines | 690 | 80.8% | 82 min | 0.58% | B+ |
| American Airlines | 646 | 72.3% | 107 min | 2.01% | C |
| SkyWest Airlines | 521 | 66.5% | 102 min | 1.34% | C |
| PSA Airlinesthin sample | 294 | 83.2% | 128 min | 0.68% | B+ |
| Republic Airwaysthin sample | 294 | 80.1% | 80 min | 1.70% | B |
| JetBlue Airwaysthin sample | 232 | 72.0% | 91 min | 0.00% | C+ |
| Alaska Airlinesthin sample | 109 | 83.5% | 51 min | 0.00% | B+ |
| Envoy Airthin sample | 54 | 77.4% | 47 min | 1.85% | B |
The spread between United and Southwest is 14 points, wide enough that it should decide the booking. On a hundred trips that is 14 more arrivals inside the on-time window.
Route by route
Busiest routes out of ATL in May
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ATL to MCO · Orlando | 722 | 72.0% | 67 min | 0.42% | C+ |
| ATL to LGA · New York | 677 | 72.9% | 79 min | 1.48% | C |
| ATL to ORD · Chicago | 596 | 72.7% | 68 min | 1.17% | C |
| ATL to DCA · Washington | 574 | 71.1% | 71 min | 2.09% | C |
| ATL to TPA · Tampa | 565 | 68.4% | 66 min | 0.35% | C+ |
| ATL to DFW · Dallas-Fort Worth | 563 | 70.9% | 91 min | 3.37% | C− |
| ATL to FLL · Fort Lauderdale | 563 | 74.3% | 63 min | 1.78% | C |
| ATL to MIA · Miami | 552 | 69.4% | 71 min | 0.54% | C+ |
| ATL to PHL · Philadelphia | 520 | 78.8% | 100 min | 0.96% | B+ |
| ATL to EWR · Newark | 519 | 82.5% | 71 min | 1.16% | B |
| ATL to BWI · Baltimore | 486 | 75.6% | 63 min | 0.62% | B+ |
| ATL to DEN · Denver | 483 | 78.2% | 56 min | 0.83% | B+ |
| ATL to BOS · Boston | 463 | 78.6% | 45 min | 0.86% | B+ |
| ATL to IAH · Houston | 444 | 68.9% | 64 min | 0.45% | C+ |
| ATL to LAX · Los Angeles | 428 | 76.0% | 52 min | 0.47% | B+ |
| ATL to LAS · Las Vegas | 407 | 68.9% | 53 min | 0.00% | C+ |
| ATL to IAD · Washington | 406 | 80.5% | 83 min | 1.23% | B |
| ATL to DTW · Detroit | 403 | 68.8% | 58 min | 0.25% | C+ |
| ATL to BNA · Nashville | 399 | 77.6% | 52 min | 2.51% | B |
| ATL to RDU · Raleigh | 390 | 81.1% | 53 min | 1.03% | B |
| ATL to CLT · Charlotte | 389 | 81.7% | 78 min | 0.00% | B+ |
| ATL to AUS · Austin | 387 | 76.1% | 51 min | 1.29% | B |
| ATL to JAX · Jacksonville | 375 | 72.8% | 48 min | 1.60% | C |
| ATL to MSY · New Orleansthin sample | 348 | 76.2% | 51 min | 0.86% | B+ |
| ATL to PBI · West Palm Beachthin sample | 341 | 79.6% | 41 min | 2.05% | B |
Delay causes
What held ATL up in May
One category carries most of the weight here. Carrier accounts for 43% of the 380,000 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.
- 43%Carrier
- 31%Late-arriving aircraft
- 22%National Airspace System
- 3%Extreme weather
- 0%Security
The largest share of delay minutes, 43%, 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 380,000 delay minutes reported here. The split is drawn from 380,436 reported delay minutes.
Cancellations sit at 1.18% against a national 0.92%, which is ordinary. Diversions add another 0.26%.
7.3% of arrivals land an hour or more late, close to the national 7.1%. 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 May
For a May trip through ATL: expect 77.2% on time and 1.18% cancelled, going by May 2026. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- Hartsfield-Jackson Atlanta International (ATL), the whole year
- ATL in July68.8%
- ATL in August78.4%
- ATL in September86.5%
- 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 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.