Best time to fly Baltimore to Pittsburgh

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

Best month

September

91.9% on time · 86 flights

Worst month

July

55.7% on time · 92 flights

Month Flights On time Cancelled When late, by
January 92 88.5% 5.43% 30 min
February 80 87.2% 2.5% 42 min
March 93 72.2% 3.23% 62 min
April 90 80% 0% 51 min
May 93 76.3% 0% 59 min
June 90 66.7% 0% 70 min
July 92 55.7% 4.35% 76 min
August 89 85.2% 1.12% 73 min
September 86 91.9% 0% 30 min
October 93 76.3% 0% 46 min
November 88 83.9% 1.14% 60 min
December 89 75.9% 2.25% 37 min

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.