Best time to fly Zurich to London

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

Best month

March

88.2% on time · 181 flights

Worst month

June

62.8% on time · 342 flights

Month Flights On time Cancelled When late, by
January 152 80.3% 3.29% 0 min
February 148 84.4% 0.68% 0 min
March 181 88.2% 1.66% 0 min
April 168 80% 1.79% 0 min
May 173 75.6% 0.58% 0 min
June 342 62.8% 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.