Best time to fly Sanford to Grand Rapids

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

Best month

March

82.5% on time · 104 flights

Worst month

July

61.3% on time · 62 flights

Month Flights On time Cancelled When late, by
January 68 63.2% 0% 57 min
February 75 70.7% 0% 62 min
March 104 82.5% 0.96% 133 min
April 85 77.6% 0% 83 min
May 60 75% 0% 60 min
June 62 63.9% 1.61% 63 min
July 62 61.3% 0% 61 min
August 46 69.6% 0% 108 min
September 38 76.3% 0% 78 min
October 63 75.4% 3.17% 108 min
November 55 67.3% 0% 56 min
December 89 75.3% 0% 71 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.