Best time to fly Singapore to London

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

Best month

March

75.7% on time · 154 flights

Worst month

February

58% on time · 141 flights

Month Flights On time Cancelled When late, by
January 155 73.2% 1.29% 0 min
February 141 58% 2.13% 0 min
March 154 75.7% 3.9% 0 min
April 150 58.4% 0.67% 0 min
May 155 71.4% 0.65% 0 min
June 302 68% 0.66% 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.