Best time to fly London to Bâle / Mulhouse

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

Best month

February

92.4% on time · 105 flights

Worst month

June

70.6% on time · 198 flights

Month Flights On time Cancelled When late, by
January 112 80.7% 2.68% 0 min
February 105 92.4% 0% 0 min
March 114 80.6% 5.26% 0 min
April 122 84.3% 0.82% 0 min
May 118 80.5% 0% 0 min
June 198 70.6% 2.02% 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.