Best Time to Fly ATL to MDW: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → Chicago Midway International
Data through July 2026 · Last updated October 18, 2026
3,526 flights were scheduled from Atlanta (ATL) to Chicago (MDW) in the last 12 months, and 76.3% of those that flew arrived on time, 1.4 points below the US average of 77.6%.
Among 3 airlines, Delta Air Lines led with 82.1% on time and Frontier Airlines was last with 65.5%.
Over 24 months, Wednesday was the most reliable day (84% on time) and July the worst month (66%).
The cancellation rate was 2.0% (US average 1.8%).
ATL to MDW 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 |
|---|---|---|---|---|
| Delta Air Lines | 82.1% | 55 min | 2.4% | 1,362 |
| Southwest Airlines | 75.4% | 59 min | 1.5% | 1,543 |
| Frontier Airlines | 65.5% | 92 min | 2.4% | 621 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to MDW
On-time arrival % by scheduled departure hour (local time), 7,270 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 10 | |
| 6am–7am | 96.2% | 1.2% | 323 |
| 7am–8am | 86.5% | 0.0% | 208 |
| 8am–9am | 87.1% | 1.7% | 830 |
| 9am–10am | 87.4% | 1.3% | 387 |
| 10am–11am | 81.9% | 2.1% | 378 |
| 11am–12pm | 85.3% | 2.0% | 763 |
| 12pm–1pm | 81.0% | 0.7% | 276 |
| 1pm–2pm | 84.5% | 0.4% | 240 |
| 2pm–3pm | 74.4% | 1.7% | 407 |
| 3pm–4pm | 80.4% | 1.4% | 560 |
| 4pm–5pm | 74.2% | 1.4% | 370 |
| 5pm–6pm | 72.5% | 0.9% | 459 |
| 6pm–7pm | 72.8% | 0.9% | 315 |
| 7pm–8pm | 54.9% | 0.4% | 249 |
| 8pm–9pm | 71.8% | 1.5% | 462 |
| 9pm–10pm | 65.9% | 1.7% | 711 |
| 10pm–11pm | 62.2% | 1.9% | 318 |
| 11pm–12am | Limited data | 4 | |
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 MDW
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) | 74.1% | -6.3 pts | 3.3% | 151 |
| Christmas & New Year (Dec 20 - Jan 3) | 74.0% | -6.5 pts | 1.0% | 296 |
| Summer peak (Jun 15 - Aug 15) | 69.3% | -11.2 pts | 2.1% | 1,304 |
| All other days | 80.4% | — | 1.2% | 5,519 |
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).