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Route · BOS → MDW · 2020–2025 BTS data

Boston to Chicago

The BOS–MDW corridor (Boston, MA → Chicago, IL) runs ahead of the national average, served by 1 carrier across roughly 861 miles.

Data updated 2026-06-13

82.1%
On-time
+3.1 pts
vs US avg
66 min
Delay when late
7,232
Flights

Cancelled

1.1%

Best Month

Mar 2025 94%

Worst Month

Sep 2025 58%

Distance

861 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 90 26 0 0 WN
Nov 2025 88 15 4 1 WN
Oct 2025 139 40 1 0 WN
Sep 2025 128 54 2 0 WN
Aug 2025 135 26 2 0 WN
Jul 2025 172 49 2 0 WN
Jun 2025 157 49 0 0 WN
May 2025 101 32 0 0 WN
Apr 2025 90 12 0 0 WN
Mar 2025 67 4 1 0 WN
Feb 2025 66 14 0 0 WN
Jan 2025 71 11 1 0 WN
Dec 2024 91 24 3 0 WN
Nov 2024 89 13 0 0 WN
Oct 2024 140 21 0 0 WN
Sep 2024 136 14 0 0 WN
Aug 2024 144 30 2 1 WN
Jul 2024 170 49 1 2 WN
Jun 2024 161 52 1 1 WN
May 2024 111 36 0 0 WN
Apr 2024 105 20 0 0 WN
Mar 2024 97 11 0 0 WN
Feb 2024 75 9 1 0 WN
Jan 2024 83 18 8 1 WN

Cancellation Rate

1.1%

29 of 2,706 flights

Diversion Rate

0.2%

6 of 2,706 flights

What the Data Says About BOS to MDW

Bureau of Transportation Statistics records show Boston to Chicago (BOS to MDW) running a 82.1% on-time rate over 7,232 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 66.3 minutes. The 861-mile corridor is served by 1 carrier, and over the last 24 months 1.1% of 2,706 flights were cancelled, 0.2% diverted.

The monthly split is wide on this route: Mar 2025 posted the strongest performance at 94% on-time, while Sep 2025 came in at just 58% - a 36-point swing worth factoring into travel timing.

Frequently Asked Questions

How often are flights delayed from BOS to MDW?
Flights from Boston to Chicago have a 82.1% on-time rate based on 7,232 flights. The average delay is 66.3 minutes. The best recent month was Mar 2025 with 94% on-time.
What is the cancellation rate for BOS to MDW?
Over the last 24 months, 1.1% of flights on this route were cancelled (29 of 2,706 flights) and 0.2% were diverted.
How far is the flight from BOS to MDW?
The flight distance from Boston (BOS) to Chicago (MDW) is approximately 861 miles. This route is served by 1 carrier.
When is the best time to fly from BOS to MDW?
The best recent month for on-time performance was Mar 2025 (94% on-time). The worst was Sep 2025 (58% on-time). Consider booking during months with historically better performance.

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Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights Editorial

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.