Best time to fly Lisbon to London

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

Best month

December

79.8% on time · 96 flights

Worst month

July

49% on time · 102 flights

Month Flights On time Cancelled When late, by
January 195 69.2% 0% 0 min
February 176 73.3% 0% 0 min
March 193 71% 0% 0 min
April 203 69.3% 0.49% 0 min
May 207 68.1% 0% 0 min
June 200 59% 0% 0 min
July 102 49% 0% 0 min
August 101 56.4% 0% 0 min
September 100 57% 0% 0 min
October 102 64.4% 0.98% 0 min
November 103 67.7% 3.88% 0 min
December 96 79.8% 2.08% 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.