Best time to fly Chicago to Bangor

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full ORD to BGR record →

Best month

November

100% on time · 2 flights

Worst month

June

68.4% on time · 120 flights

Month Flights On time Cancelled When late, by
April 44 69% 4.55% 97 min
May 81 76.5% 0% 82 min
June 120 68.4% 4.17% 68 min
July 122 80.3% 0% 93 min
August 109 85.8% 0.92% 60 min
September 108 87% 0% 150 min
October 109 79.8% 0% 37 min
November 2 100% 0%

What a seasonal pattern can and cannot tell you

Months differ for reasons that repeat — summer thunderstorms in the American interior, winter fog and de-icing in northern Europe, school holidays filling every seat and leaving no slack in the schedule. Those are real and they come back each year.

What the pattern cannot do is forecast a particular flight. A quiet month has late days and a bad month has punctual ones. Treat this as a way to choose between two dates you are indifferent about, not as a promise.