Best time to fly Dundee to London

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

Best month

June

93.2% on time · 60 flights

Worst month

December

56.8% on time · 50 flights

Month Flights On time Cancelled When late, by
January 95 73.3% 5.26% 0 min
February 88 88.5% 1.14% 0 min
March 94 84.6% 3.19% 0 min
April 62 83.3% 3.23% 0 min
May 62 85.2% 1.61% 0 min
June 60 93.2% 1.67% 0 min
July 31 87.1% 0% 0 min
August 32 83.3% 6.25% 0 min
September 30 70% 0% 0 min
October 37 81.1% 0% 0 min
November 45 91.1% 0% 0 min
December 50 56.8% 12% 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.