Best time to fly Chicago to Miami

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

Best month

October

89.1% on time · 55 flights

Worst month

January

66.1% on time · 109 flights

Month Flights On time Cancelled When late, by
January 109 66.1% 0% 44 min
February 102 78.2% 0.98% 98 min
March 166 73.6% 1.81% 70 min
April 123 79.5% 0.81% 57 min
May 106 77.4% 0% 75 min
June 71 67.6% 0% 35 min
July 105 68% 3.81% 62 min
August 81 70.1% 2.47% 49 min
September 69 85.1% 0% 81 min
October 55 89.1% 0% 74 min
November 86 81.9% 3.49% 63 min
December 106 67.3% 0.94% 78 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.