Best time to fly Toronto to London

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

Best month

April

80.7% on time · 199 flights

Worst month

February

53.1% on time · 132 flights

Month Flights On time Cancelled When late, by
January 143 55.6% 0.7% 0 min
February 132 53.1% 3.03% 0 min
March 155 78.7% 3.23% 0 min
April 199 80.7% 1.01% 0 min
May 206 71.6% 0.97% 0 min
June 401 71.7% 1.25% 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.