BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
BOS→MDW

Boston, MA (BOS) to Chicago, IL (MDW) flight delay odds

71.4% of 1,382 official scheduled BOS-to-MDW flights arrived on time; 17.4% arrived at least 30 minutes late and 1.8% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALGenerally reliable
71.4%arrived on time
17.4%30+ min late
1.8%cancelled
1,382scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late9.0%all scheduled flights
120+ minutes late3.1%all scheduled flights
Diverted0.4%did not reach as scheduled
Average arrival+10.6 mincompleted flights

Which departure time was most reliable for BOS to MDW?

Among qualifying BOS-to-MDW departure window results, Late morning had the highest on-time rate: 92.7% of 178 flights. Evening was lowest at 40.9% across 345 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning44389.8%4.5%1.6%
Late morning17892.7%3.4%0.0%
Afternoon39569.6%17.7%1.0%
Evening34540.9%39.4%3.8%

Which weekday was most reliable for BOS to MDW?

Among qualifying BOS-to-MDW weekday results, Saturday had the highest on-time rate: 78.8% of 184 flights. Sunday was lowest at 64.4% across 208 flights.

DayFlightsOn time30+ minCancelled
Monday20866.3%19.7%2.9%
Tuesday18775.4%15.0%1.6%
Wednesday17878.1%15.2%1.1%
Thursday20666.0%18.9%2.9%
Friday21173.0%18.0%0.9%
Saturday18478.8%9.2%1.6%
Sunday20864.4%24.0%1.4%

Which airline was most reliable for BOS to MDW?

Only Southwest Airlines met the BOS-to-MDW airline threshold: 71.4% of 1,382 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines1,38271.4%17.4%1.8%

Which month was most reliable for BOS to MDW?

Among qualifying BOS-to-MDW month results, January 2026 had the highest on-time rate: 81.2% of 69 flights. September 2025 was lowest at 56.2% across 128 flights.

MonthFlightsOn time30+ minCancelled
July 202517270.3%19.8%1.2%
August 202513579.3%14.1%1.5%
September 202512856.2%30.5%1.6%
October 202513970.5%22.3%0.7%
November 20258877.3%11.4%4.5%
December 20259071.1%17.8%0.0%
January 20266981.2%4.3%2.9%
February 20266373.0%9.5%7.9%
March 202611365.5%17.7%2.7%
April 202611979.0%10.9%0.0%
May 202612373.2%13.8%0.0%
June 202614367.8%22.4%2.8%

What drove BOS to MDW delay minutes?

Late aircraft was the largest recorded BOS-to-MDW delay category, accounting for 58.6% of 22,403 BTS-attributed delay minutes during July 2025–June 2026.

Airline22.0%
Late aircraft58.6%
National airspace17.2%
Weather2.3%
Security0.0%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.