Best time to fly Chicago to Kalispell

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

Best month

November

100% on time · 1 flights

Worst month

February

60% on time · 20 flights

Month Flights On time Cancelled When late, by
January 18 77.8% 0% 74 min
February 20 60% 0% 31 min
March 32 63.3% 3.13% 93 min
April 4 75% 0% 29 min
May 43 81.4% 0% 91 min
June 185 69% 0.54% 57 min
July 189 68.8% 1.06% 89 min
August 181 77% 1.66% 88 min
September 150 86.7% 0% 67 min
October 64 78.1% 0% 42 min
November 1 100% 0%
December 35 71.4% 0% 65 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.