Best time to fly Amsterdam to London

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

Best month

April

85.2% on time · 467 flights

Worst month

January

66.5% on time · 491 flights

Month Flights On time Cancelled When late, by
January 491 66.5% 2.85% 0 min
February 453 82.9% 0.88% 0 min
March 491 76.6% 4.28% 0 min
April 467 85.2% 0% 0 min
May 481 80.6% 0.42% 0 min
June 886 73.4% 2.48% 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.