PlainFlights

Route · BOS → MDW · 2020–2025 BTS data

Boston to Chicago

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), BOS to MDW (Boston to Chicago) ranks #1746 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

82.1%
On-time
+3.1 pts
vs US avg
66 min
Delay when late
7,232
Flights
#1746 of 4927
Corpus placement

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

BOS–MDW seasonal on-time pattern

Best: March (90.3%) · weakest: June (75.7%)

70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 81.7%

Strongest calendar month

March

90.3% on-time · ~83 flights/mo

Busiest calendar month

July

~140 flights/mo avg

Weakest calendar month

June

75.7% on-time · ~123 flights/mo

Cancellation Rate

1.1%

29 of 2,706 flights

Diversion Rate

0.2%

6 of 2,706 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

BOS - Boston

Full on-time, delay-cause, and seasonal performance for Boston, MA.

BOS on-time profile

MDW - Chicago

Full on-time, delay-cause, and seasonal performance for Chicago, IL.

MDW on-time profile

Compare the two airports

See BOS and MDW side by side on delays, cancellations, and reliability.

Compare BOS vs MDW

Origin-hub reliability standing

Mid-pack among BOS departures

From BOS, this corridor sits with 49 other 75–85% on-time routes out of 60 tracked departures, not the hub's reliability leaders (6 at ≥85%) and not the softest ( 5 below 75%). Destination: Chicago · fleet on-time rank #2298 of 4927.

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.

On the multi-year calendar, BOS–MDW peaks in March at 90.3% on-time while July carries the heaviest traffic (~140 flights per month) ; the softest month is June at 75.7%, a 14.6-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does BOS to MDW rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, BOS to MDW ranks #1746 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
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.

Airports on this route

BOS Airport

Boston
MDW Airport

Chicago
Data source

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

Read our methodology - how this data is sourced, computed, and verified.

Using BOS–MDW data

BOS–MDW runs 3.1 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare BOS and MDW airport profiles: delay causes and top routes differ even on the same corridor. BOS airport
  • If your dates flex, March (90.3% on-time) beats June (75.7%) on this corridor. Seasonal chart
  • 4 other routes post a similar 82.1% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

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

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.