Best time to fly Birmingham to Belfast

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

Best month

April

88.7% on time · 424 flights

Worst month

July

65.6% on time · 198 flights

Month Flights On time Cancelled When late, by
January 350 72.8% 4.57% 0 min
February 406 81.5% 0% 0 min
March 456 85.7% 0% 0 min
April 424 88.7% 0% 0 min
May 429 74.5% 0.23% 0 min
June 416 73.2% 0.48% 0 min
July 198 65.6% 3.03% 0 min
August 197 73.1% 2.03% 0 min
September 211 80% 0.47% 0 min
October 223 82.8% 0.9% 0 min
November 215 85.7% 2.33% 0 min
December 238 77.6% 2.52% 0 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.