Best time to fly London to Zurich

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

Best month

March

78.1% on time · 181 flights

Worst month

June

36% on time · 342 flights

Month Flights On time Cancelled When late, by
January 153 70.7% 3.92% 0 min
February 149 73% 0.67% 0 min
March 181 78.1% 1.66% 0 min
April 170 63% 2.94% 0 min
May 173 51.2% 0.58% 0 min
June 342 36% 2.63% 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.