Best time to fly Cincinnati to Seattle

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

Best month

October

89.3% on time · 122 flights

Worst month

December

59.5% on time · 117 flights

Month Flights On time Cancelled When late, by
January 116 80.2% 3.45% 48 min
February 104 62.1% 0.96% 63 min
March 118 69.3% 2.54% 59 min
April 120 83.3% 0% 69 min
May 124 88.6% 0.81% 42 min
June 160 74.4% 0% 75 min
July 154 70.5% 3.25% 54 min
August 143 72.7% 0% 49 min
September 120 85.8% 0% 65 min
October 122 89.3% 0.82% 34 min
November 114 81.6% 0% 37 min
December 117 59.5% 0.85% 45 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.