Best Time to Fly ATL to ORD: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → Chicago O'Hare International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 70.7% of Atlanta (ATL) to Chicago (ORD) flights arrived on time (6,440 scheduled flights). That is 6.9 points below the national average of 77.6%.
SkyWest Airlines was the most punctual of the 8 airlines on the route at 84.2%, while Frontier Airlines trailed at 64.2%.
September has been the best month (83% on time) and Friday the weakest day of the week (70%).
2.4% of flights were cancelled, versus 1.8% nationally.
ATL to ORD on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlines | 84.2% | 88 min | 5.0% | 40 |
| Spirit Airlines | 79.5% | 32 min | 0.0% | 45 |
| United Airlines | 74.8% | 91 min | 1.6% | 1,668 |
| American Airlines | 72.2% | 106 min | 2.4% | 672 |
| Envoy Air | 71.3% | 83 min | 2.2% | 363 |
| Delta Air Lines | 69.2% | 62 min | 2.3% | 2,630 |
| Republic Airways | 69.0% | 79 min | 6.2% | 305 |
| Frontier Airlines | 64.2% | 110 min | 3.1% | 712 |
| PSA Airlines | Limited data | 5 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to ORD
On-time arrival % by scheduled departure hour (local time), 12,369 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 91.2% | 0.0% | 68 |
| 6am–7am | 89.8% | 1.6% | 675 |
| 7am–8am | 87.2% | 2.0% | 1,102 |
| 8am–9am | 79.8% | 1.4% | 482 |
| 9am–10am | 77.6% | 1.7% | 774 |
| 10am–11am | 80.3% | 1.2% | 806 |
| 11am–12pm | 84.4% | 1.3% | 997 |
| 12pm–1pm | 77.3% | 1.0% | 584 |
| 1pm–2pm | 80.1% | 1.2% | 803 |
| 2pm–3pm | 70.1% | 2.0% | 150 |
| 3pm–4pm | 70.3% | 1.7% | 1,657 |
| 4pm–5pm | 61.6% | 0.8% | 266 |
| 5pm–6pm | 49.9% | 2.4% | 795 |
| 6pm–7pm | 62.5% | 2.2% | 854 |
| 7pm–8pm | 62.6% | 3.2% | 785 |
| 8pm–9pm | 58.1% | 2.4% | 500 |
| 9pm–10pm | 62.1% | 4.2% | 217 |
| 10pm–11pm | 71.0% | 3.0% | 819 |
| 11pm–12am | 60.0% | 0.0% | 35 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ATL to ORD
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 61.8% | -13.5 pts | 4.4% | 227 |
| Christmas & New Year (Dec 20 - Jan 3) | 69.2% | -6.1 pts | 1.7% | 413 |
| Summer peak (Jun 15 - Aug 15) | 68.0% | -7.3 pts | 2.7% | 2,313 |
| All other days | 75.3% | — | 1.6% | 9,416 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).