Best time to fly Stockholm to London

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

Best month

May

93.3% on time · 180 flights

Worst month

June

79.3% on time · 400 flights

Month Flights On time Cancelled When late, by
January 222 79.6% 0.45% 0 min
February 225 92.9% 0% 0 min
March 233 89.4% 3% 0 min
April 202 91.1% 0% 0 min
May 180 93.3% 0% 0 min
June 400 79.3% 0.75% 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.