Best Time to Fly BWI to MDW: On-Time Stats by Hour & Airline
Baltimore/Washington International Thurgood Marshall → Chicago Midway International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 76.0% of Baltimore (BWI) to Chicago (MDW) flights arrived on time (1,838 scheduled flights). That is 1.6 points below the national average of 77.6%.
Southwest Airlines was the most punctual of the 2 airlines on the route at 76.0%, while Frontier Airlines trailed at 75.4%.
September has been the best month (84% on time) and Friday the weakest day of the week (74%).
2.2% of flights were cancelled, versus 1.8% nationally.
BWI 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 |
|---|---|---|---|---|
| Southwest Airlines | 76.0% | 60 min | 2.2% | 1,767 |
| Frontier Airlines | 75.4% | 86 min | 1.4% | 71 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly BWI to MDW
On-time arrival % by scheduled departure hour (local time), 3,810 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 94.1% | 0.2% | 441 |
| 7am–8am | 89.2% | 2.1% | 284 |
| 8am–9am | 89.8% | 0.0% | 137 |
| 9am–10am | 80.7% | 1.5% | 137 |
| 10am–11am | 86.2% | 2.8% | 211 |
| 11am–12pm | 85.9% | 1.1% | 93 |
| 12pm–1pm | 77.3% | 1.7% | 238 |
| 1pm–2pm | 84.8% | 0.0% | 231 |
| 2pm–3pm | 77.0% | 1.4% | 141 |
| 3pm–4pm | 81.8% | 0.6% | 156 |
| 4pm–5pm | 70.2% | 2.2% | 315 |
| 5pm–6pm | 76.9% | 0.3% | 292 |
| 6pm–7pm | 56.8% | 2.5% | 243 |
| 7pm–8pm | 67.8% | 1.6% | 316 |
| 8pm–9pm | 61.7% | 2.8% | 318 |
| 9pm–10pm | 55.2% | 3.0% | 100 |
| 10pm–11pm | 61.3% | 4.5% | 157 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on BWI 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) | 77.5% | -2.7 pts | 6.4% | 78 |
| Christmas & New Year (Dec 20 - Jan 3) | 71.1% | -9.0 pts | 1.3% | 151 |
| Summer peak (Jun 15 - Aug 15) | 65.0% | -15.2 pts | 2.9% | 738 |
| All other days | 80.2% | — | 1.2% | 2,843 |
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).