Best time to fly Minneapolis to Seattle

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

Best month

April

93.3% on time · 197 flights

Worst month

December

52.2% on time · 208 flights

Month Flights On time Cancelled When late, by
January 167 68.1% 0.6% 65 min
February 157 81.3% 0.64% 46 min
March 200 66.7% 6% 55 min
April 197 93.3% 0.51% 57 min
May 226 84.4% 0.88% 65 min
June 252 83.3% 0% 69 min
July 295 82.4% 1.02% 60 min
August 292 87% 0% 59 min
September 264 92% 0.76% 66 min
October 230 89.4% 1.3% 35 min
November 202 83% 0.99% 43 min
December 208 52.2% 0.48% 63 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.