Airport month record
ORDAUG
Chicago O'Hare International in August 2025
- Departures
- 30,090
- Month
- August 2025
- National, same month
- 77.4%
- Carriers
- 12
Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at ORD, see live FAA status.
ORD in August sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.4%. The late ones land a little over an hour behind schedule. That rests on 30,090 flights, of which Republic Airways flew 2,047 at 81.9% on time.
Republic Airways is the most reliable of the eight carriers covered here at 81.9% on time across 2,047 flights.
Key figures
On time
73.9%
Arrivals under 15 minutes late, of 29,256 completed departures
Avg delay
80 min
Across delayed arrivals only, not all flights
Cancelled
2.48%
Nationally in August: 1.08%
Whole year
71.0%
ORD across all twelve months
These figures cover 30,090 departures from Chicago O'Hare 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 ORD's other months
Against ORD's own year, August ran 3 points better than the twelve-month rate of 71.0%, which makes it number four of twelve months, best first. Either side of it, July ran 63.9% on time and September 79.2%, so a trip moved by a few weeks would have landed in a worse stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 30,503 | 63.9% | 82 min | 2.60% | D |
| August 2025 (this page) | 30,090 | 73.9% | 80 min | 2.48% | C |
| September 2025 | 28,867 | 79.2% | 68 min | 0.42% | B+ |
| October 2025 | 31,096 | 74.7% | 64 min | 0.23% | C+ |
| November 2025 | 28,703 | 73.3% | 82 min | 5.59% | C− |
| December 2025 | 27,790 | 61.0% | 91 min | 2.53% | D |
| January 2026 | 25,131 | 67.4% | 79 min | 3.74% | C− |
| February 2026 | 25,538 | 73.7% | 67 min | 1.11% | C |
| March 2026 | 31,373 | 65.9% | 85 min | 5.71% | C− |
| April 2026 | 33,206 | 69.7% | 75 min | 3.54% | C− |
| May 2026 | 33,733 | 76.1% | 73 min | 1.01% | B |
| June 2026 | 31,374 | 71.3% | 80 min | 3.19% | C− |
Departure window
The best time of day to leave ORD in August
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 24 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am3,378 flights88.1%
- 8am–11am6,485 flights81.7%
- 11am–2pm4,964 flights78.2%
- 2pm–5pm5,644 flights69.1%
- 5pm–8pm5,523 flights63.7%
- 8pm–5am4,096 flights63.6%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.6% on time, against 88.1% 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 8am–11am window is the busiest, with 6,485 flights scheduled in it.
Across the week, Wednesday is the strongest day at 79.9% on time and Monday the weakest at 67.6%. 12 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at ORD in August
The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.9% of the time; American Airlines manages 65.7%. Sample sizes sit next to every figure, because a two-point gap across 5,499 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 8,616 | 73.9% | 74 min | 1.94% | C |
| SkyWest Airlines | 6,574 | 72.4% | 84 min | 3.45% | C− |
| American Airlines | 5,499 | 65.7% | 89 min | 2.71% | C |
| Envoy Air | 4,295 | 81.2% | 53 min | 2.47% | B |
| Republic Airways | 2,047 | 81.9% | 76 min | 2.54% | B |
| Delta Air Lines | 1,075 | 79.6% | 104 min | 1.21% | B |
| Spirit Airlines | 504 | 79.4% | 101 min | 0.79% | B+ |
| Southwest Airlines | 408 | 73.3% | 72 min | 0.74% | C+ |
| Frontier Airlinesthin sample | 353 | 71.3% | 99 min | 2.27% | C |
| Alaska Airlinesthin sample | 327 | 70.8% | 45 min | 1.53% | C |
| PSA Airlinesthin sample | 281 | 63.9% | 154 min | 4.27% | D− |
| JetBlue Airwaysthin sample | 111 | 89.9% | 82 min | 0.90% | A+ |
SkyWest Airlines cancels 3.5% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Busiest routes out of ORD in August
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| ORD to LGA · New York | 973 | 70.9% | 84 min | 3.08% | C− |
| ORD to BOS · Boston | 685 | 73.8% | 78 min | 2.19% | C |
| ORD to LAX · Los Angeles | 664 | 72.3% | 90 min | 1.66% | C |
| ORD to SEA · Seattle | 602 | 68.5% | 66 min | 1.99% | C |
| ORD to DEN · Denver | 598 | 72.8% | 74 min | 1.51% | C |
| ORD to DCA · Washington | 585 | 71.9% | 82 min | 2.74% | C |
| ORD to DFW · Dallas-Fort Worth | 582 | 65.6% | 95 min | 3.44% | C− |
| ORD to ATL · Atlanta | 573 | 78.4% | 91 min | 1.75% | B |
| ORD to MSP · Minneapolis | 542 | 69.2% | 84 min | 0.92% | C+ |
| ORD to IAH · Houston | 531 | 72.1% | 84 min | 2.07% | C |
| ORD to SFO · San Francisco | 523 | 73.0% | 77 min | 2.68% | C |
| ORD to DTW · Detroit | 499 | 78.5% | 66 min | 2.20% | B |
| ORD to MCO · Orlando | 495 | 69.5% | 90 min | 1.62% | C |
| ORD to EWR · Newark | 493 | 63.2% | 85 min | 1.22% | D |
| ORD to LAS · Las Vegas | 485 | 78.7% | 68 min | 2.06% | B |
| ORD to PHL · Philadelphia | 438 | 71.7% | 93 min | 2.97% | C |
| ORD to CLE · Cleveland | 421 | 71.0% | 82 min | 4.28% | C− |
| ORD to PHX · Phoenix | 416 | 73.2% | 81 min | 2.64% | C |
| ORD to BNA · Nashville | 412 | 75.1% | 85 min | 2.43% | B |
| ORD to IND · Indianapolis | 410 | 78.0% | 94 min | 3.41% | B− |
| ORD to CMH · Columbus | 408 | 77.4% | 85 min | 3.43% | B− |
| ORD to CVG · Cincinnati | 407 | 78.5% | 75 min | 2.95% | B |
| ORD to MKE · Milwaukee | 399 | 68.1% | 91 min | 5.51% | C− |
| ORD to PIT · Pittsburghthin sample | 343 | 80.6% | 88 min | 2.33% | B |
| ORD to MIA · Miamithin sample | 334 | 75.8% | 56 min | 1.50% | B |
Delay causes
What held ORD 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 613,000 reported delay minutes.
- 42%Late-arriving aircraft
- 31%Carrier
- 15%National Airspace System
- 12%Extreme weather
- 0%Security
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the comparison with the other months below is the more useful view of the risk. The national share is 7%, so this operation carries roughly 1.7 times the usual weather exposure. The split is drawn from 612,882 reported delay minutes.
Cancellations sit at 2.48% against a national 1.08%, which is ordinary. Diversions add another 0.29%.
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.7% of arrivals land a full hour or more behind schedule, against 8.2% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
What to do with this
Flying from ORD in August
For a August trip through ORD: expect 73.9% on time and 2.48% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.
Related
Where to go next
- Chicago O'Hare International (ORD), the whole year
- ORD in July63.9%
- ORD in September79.2%
- ORD in October74.7%
- ORD in November73.3%
- ORD in December61.0%
- ORD in January67.4%
- ORD in February73.7%
- ORD in March65.9%
- ORD in April69.7%
- ORD in May76.1%
- ORD in June71.3%
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.