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

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

65.6% of 7,642 official scheduled ORD-to-BOS flights arrived on time; 23.1% arrived at least 30 minutes late and 2.8% 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 SIGNALVariable
65.6%arrived on time
23.1%30+ min late
2.8%cancelled
7,642scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late14.1%all scheduled flights
120+ minutes late5.5%all scheduled flights
Diverted0.2%did not reach as scheduled
Average arrival+17.9 mincompleted flights

Which departure time was most reliable for ORD to BOS?

Among qualifying ORD-to-BOS departure window results, Early morning had the highest on-time rate: 83.0% of 1,964 flights. Afternoon was lowest at 54.0% across 1,897 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning1,96483.0%8.9%2.1%
Late morning1,65871.0%18.3%1.7%
Afternoon1,89754.0%34.6%2.6%
Evening1,91154.5%30.2%4.6%
Night21264.6%23.6%2.8%

Which weekday was most reliable for ORD to BOS?

Among qualifying ORD-to-BOS weekday results, Saturday had the highest on-time rate: 74.0% of 909 flights. Monday was lowest at 60.8% across 1,170 flights.

DayFlightsOn time30+ minCancelled
Monday1,17060.8%26.5%5.2%
Tuesday1,07269.1%20.1%2.6%
Wednesday1,04368.1%22.1%1.0%
Thursday1,14162.8%24.9%3.4%
Friday1,15165.1%23.2%1.4%
Saturday90974.0%16.5%1.2%
Sunday1,15661.5%26.5%4.2%

Which airline was most reliable for ORD to BOS?

Among qualifying ORD-to-BOS airline results, Envoy Air had the highest on-time rate: 80.4% of 444 flights. American Airlines was lowest at 58.0% across 2,126 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines2,68067.2%23.4%1.9%
American Airlines2,12658.0%28.6%2.8%
Delta Air Lines96266.9%21.9%3.0%
Republic Airways89666.4%18.8%5.5%
JetBlue Airways53471.2%18.2%2.6%
Envoy Air44480.4%11.3%2.5%

Which month was most reliable for ORD to BOS?

Among qualifying ORD-to-BOS month results, May 2026 had the highest on-time rate: 75.8% of 740 flights. September 2025 was lowest at 55.6% across 660 flights.

MonthFlightsOn time30+ minCancelled
July 202567362.1%26.2%2.8%
August 202568572.1%19.3%2.2%
September 202566055.6%33.3%0.6%
October 202569557.0%30.9%0.9%
November 202563969.3%20.8%4.7%
December 202555765.2%25.1%0.9%
January 202650064.6%19.4%6.4%
February 202650366.4%17.3%6.8%
March 202659862.9%22.6%5.2%
April 202664168.3%20.1%2.2%
May 202674075.8%17.8%0.4%
June 202675166.4%22.2%2.7%

What drove ORD to BOS delay minutes?

Late aircraft was the largest recorded ORD-to-BOS delay category, accounting for 42.7% of 186,626 BTS-attributed delay minutes during July 2025–June 2026.

Airline19.2%
Late aircraft42.7%
National airspace33.0%
Weather5.0%
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.