Best time to fly London to Paris (Roissy-en-France

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

Best month

April

87.3% on time · 380 flights

Worst month

January

71.1% on time · 413 flights

Month Flights On time Cancelled When late, by
January 413 71.1% 1.94% 0 min
February 376 85.3% 0.27% 0 min
March 418 77.9% 4.55% 0 min
April 380 87.3% 0.26% 0 min
May 376 82.3% 0.8% 0 min
June 723 73.8% 2.21% 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.