Best time to fly Istanbul to London

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

Best month

March

94.6% on time · 277 flights

Worst month

September

59.7% on time · 159 flights

Month Flights On time Cancelled When late, by
January 275 78.5% 0% 0 min
February 245 80.7% 0.41% 0 min
March 277 94.6% 0% 0 min
April 294 89.8% 0.34% 0 min
May 279 83.5% 0% 0 min
June 273 76.6% 0% 0 min
July 163 66.9% 0% 0 min
August 164 73.8% 0% 0 min
September 159 59.7% 0% 0 min
October 163 71% 0.61% 0 min
November 123 88.6% 0% 0 min
December 125 88% 0% 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.