FlyerIntel Research
Which Airports Suffer Most in Summer
Every major US airport gets worse in the summer. Some get far worse than others.
Published August 29, 2026 · Source period July 2023 – July 2026
Summary
MCO (Orlando) loses the most ground in summer: on-time arrivals fall 10.8 percentage points from the shoulder months of April, May, September and October to June through August. The average across the 64 airports measured is 6.5 points. HNL is the least affected, at 0.7 points.
Key findings
- MCO shows the steepest summer decline at 10.8 percentage points.
- The average major airport loses 6.5 points of on-time performance in summer.
- HNL is the most summer-resistant of the airports measured.
- MCO's weakest month overall is July at 63.4%, against 82.2% in November.
Summer decline in on-time arrivals, percentage points
Seasonal spread by airport
| Airport | City | Best month | On time | Worst month | On time | Spread | Summer drop |
|---|---|---|---|---|---|---|---|
| MCO | Orlando | November | 82.2% | July | 63.4% | 18.8 pts | 10.8 pts |
| BWI | Baltimore | November | 84.3% | July | 62.9% | 21.4 pts | 10.6 pts |
| PHL | Philadelphia | November | 83.4% | July | 65.4% | 18 pts | 10.2 pts |
| MIA | Miami | October | 82.2% | July | 63.4% | 18.9 pts | 10.1 pts |
| DEN | Denver | November | 82.5% | June | 67.0% | 15.5 pts | 9.9 pts |
| MDW | Chicago | November | 84.8% | July | 65.1% | 19.7 pts | 9.9 pts |
| CLT | Charlotte | November | 83.5% | July | 62.0% | 21.4 pts | 9.8 pts |
| MYR | Myrtle Beach | October | 87.3% | July | 71.0% | 16.4 pts | 9.7 pts |
| JFK | New York | November | 83.7% | July | 66.9% | 16.9 pts | 9.1 pts |
| BUF | Buffalo | October | 85.9% | July | 71.3% | 14.6 pts | 8.9 pts |
| IAD | Washington | October | 88.3% | July | 71.7% | 16.6 pts | 8.7 pts |
| JAX | Jacksonville | October | 86.0% | July | 69.5% | 16.5 pts | 8.7 pts |
| FLL | Fort Lauderdale | October | 80.7% | July | 64.7% | 16 pts | 8.5 pts |
| MSP | Minneapolis | October | 87.6% | June | 74.0% | 13.6 pts | 8.5 pts |
| IAH | Houston | February | 83.8% | June | 67.7% | 16.1 pts | 8.4 pts |
| TPA | Tampa | November | 85.2% | July | 68.5% | 16.7 pts | 8.3 pts |
| ATL | Atlanta | October | 86.6% | July | 67.4% | 19.2 pts | 8 pts |
| SJU | San Juan | November | 81.7% | August | 68.7% | 13 pts | 8 pts |
| EWR | Newark | September | 82.3% | July | 65.3% | 17 pts | 7.8 pts |
| DTW | Detroit | October | 87.6% | January | 69.9% | 17.8 pts | 7.6 pts |
| ORD | Chicago | October | 80.8% | July | 67.4% | 13.5 pts | 7.6 pts |
| RSW | Fort Myers | October | 86.4% | July | 70.9% | 15.6 pts | 7.5 pts |
| DFW | Dallas–Fort Worth | October | 80.1% | June | 63.5% | 16.6 pts | 7.4 pts |
| RDU | Raleigh–Durham | October | 84.0% | July | 70.4% | 13.7 pts | 7.4 pts |
| ILM | Wilmington | November | 87.1% | July | 74.1% | 13 pts | 7.3 pts |
| DCA | Washington | October | 84.1% | July | 67.4% | 16.7 pts | 7.1 pts |
| SEA | Seattle | October | 83.9% | July | 73.5% | 10.4 pts | 7.1 pts |
| STL | St. Louis | November | 84.8% | July | 70.0% | 14.8 pts | 7 pts |
| CLE | Cleveland | October | 86.4% | July | 74.9% | 11.5 pts | 6.9 pts |
| ABE | Allentown | October | 89.3% | July | 75.3% | 14 pts | 6.7 pts |
| MSY | New Orleans | November | 84.1% | July | 69.4% | 14.7 pts | 6.6 pts |
| OMA | Omaha | September | 87.1% | June | 75.0% | 12.2 pts | 6.5 pts |
| LGA | New York | September | 83.2% | July | 69.4% | 13.8 pts | 6.4 pts |
| PIT | Pittsburgh | November | 87.6% | July | 76.0% | 11.6 pts | 6.4 pts |
| BNA | Nashville | November | 84.1% | July | 68.8% | 15.4 pts | 6.2 pts |
| MEM | Memphis | October | 87.0% | July | 74.4% | 12.7 pts | 6.2 pts |
| LAS | Las Vegas | November | 83.7% | July | 68.8% | 14.9 pts | 5.9 pts |
| ANC | Anchorage | May | 88.2% | January | 77.9% | 10.4 pts | 5.8 pts |
| HOU | Houston | September | 85.3% | June | 68.3% | 17 pts | 5.8 pts |
| BOS | Boston | November | 83.3% | July | 69.7% | 13.5 pts | 5.7 pts |
| PHX | Phoenix | September | 84.7% | July | 73.5% | 11.2 pts | 5.4 pts |
| SAN | San Diego | January | 82.8% | July | 71.7% | 11 pts | 5.4 pts |
| CHS | Charleston | November | 85.9% | July | 72.2% | 13.7 pts | 5.3 pts |
| IND | Indianapolis | October | 87.2% | July | 76.1% | 11.1 pts | 5.3 pts |
| MCI | Kansas City | November | 85.3% | July | 75.2% | 10.1 pts | 5.3 pts |
| MKE | Milwaukee | October | 85.8% | July | 75.8% | 9.9 pts | 5.1 pts |
| PDX | Portland | November | 86.4% | July | 78.5% | 7.9 pts | 5 pts |
| LAX | Los Angeles | September | 85.8% | July | 76.4% | 9.4 pts | 4.9 pts |
| SAT | San Antonio | November | 86.9% | June | 75.6% | 11.3 pts | 4.9 pts |
| SLC | Salt Lake City | October | 88.1% | July | 78.8% | 9.3 pts | 4.9 pts |
| DAL | Dallas | February | 82.5% | June | 64.1% | 18.4 pts | 4.8 pts |
| OAK | Oakland | November | 86.8% | June | 76.6% | 10.2 pts | 4.8 pts |
| CMH | Columbus | October | 86.7% | July | 76.8% | 9.9 pts | 4.7 pts |
| AUS | Austin | September | 83.2% | June | 70.9% | 12.3 pts | 4.5 pts |
| SNA | Santa Ana | September | 85.5% | July | 77.1% | 8.4 pts | 4.3 pts |
| ABQ | Albuquerque | February | 87.0% | July | 77.5% | 9.5 pts | 4.1 pts |
| SFO | San Francisco | October | 83.2% | July | 73.6% | 9.6 pts | 4 pts |
| SMF | Sacramento | February | 86.4% | July | 78.7% | 7.7 pts | 4 pts |
| SJC | San Jose | January | 87.5% | June | 78.4% | 9.1 pts | 3.9 pts |
| ONT | Ontario | February | 87.4% | June | 79.3% | 8.1 pts | 3.6 pts |
| TUS | Tucson | September | 87.4% | June | 79.6% | 7.8 pts | 3.2 pts |
| SBA | Santa Barbara | January | 85.7% | June | 78.8% | 6.9 pts | 1.8 pts |
| BUR | Burbank | January | 86.0% | June | 79.1% | 6.9 pts | 1.5 pts |
| HNL | Honolulu | September | 90.6% | January | 82.0% | 8.6 pts | 0.7 pts |
Convective weather, not heat
Summer disruption in the US is largely a thunderstorm problem rather than a temperature one. Convective weather builds through the afternoon, is difficult to forecast more than a few hours ahead, and closes airspace rather than airports, which is why it propagates so widely. Airports exposed to reliable afternoon convection, or that depend on airspace that is, take the largest hit. Airports in drier or more stable summer climates barely move. The pattern compounds with the time-of-day effect: an evening departure in July is the least reliable combination in the dataset.
Pages for what this report covers
Airports: Orlando (MCO) · Baltimore (BWI) · Philadelphia (PHL) · Miami (MIA) · Denver (DEN) · Chicago (MDW) · Charlotte (CLT) · Myrtle Beach (MYR) · New York (JFK) · Buffalo (BUF)
Methodology
Calculated by FlyerIntel from 21,708,321 individual flight records in the US Department of Transportation Bureau of Transportation Statistics Reporting Carrier On-Time Performance dataset, covering July 2023 through July 2026. Following BTS methodology, a flight counts as delayed when it arrives 15 or more minutes after its scheduled arrival time. Cancelled and diverted flights have no arrival time and are excluded from on-time rates rather than counted as late; cancellation rates are reported separately. Full definitions are published at /methodology/. Each calendar month is pooled across every year in the period, and only included where that month has at least two years of data and 120 flights. "Summer drop" is the difference between the mean on-time rate for April, May, September and October and the mean for June, July and August.
Limitations
The source dataset covers scheduled domestic flights operated by carriers above the DOT reporting threshold; smaller carriers and international flights are not included. Flights sold under a mainline brand but flown by a regional carrier are attributed to the operating carrier, which is how the DOT records them. Past performance describes what has happened and is not a prediction about any individual flight. Seasonal comparison over a small number of years can be influenced by an unusually severe or mild individual season.
Sources
- FlyerIntel analysis — FlyerIntel · source
- Reporting Carrier On-Time Performance — US Department of Transportation, Bureau of Transportation Statistics · source
Full FlyerIntel methodology · Report a problem with this analysis