Best time to fly Palm Springs to Seattle

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

Best month

September

94.4% on time · 90 flights

Worst month

August

80.8% on time · 73 flights

Month Flights On time Cancelled When late, by
January 183 90.4% 2.73% 117 min
February 166 84.7% 1.81% 111 min
March 198 83.1% 1.52% 69 min
April 216 94% 0% 57 min
May 123 86.8% 1.63% 55 min
June 69 85.3% 1.45% 52 min
July 62 83.3% 3.23% 44 min
August 73 80.8% 0% 35 min
September 90 94.4% 1.11% 45 min
October 149 85.7% 0.67% 48 min
November 165 89.6% 0.61% 42 min
December 155 81.6% 1.29% 58 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.