Best time to fly Miami to São Paulo

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

Best month

November

73.6% on time · 140 flights

Worst month

March

51.5% on time · 296 flights

Month Flights On time Cancelled When late, by
January 300 58.2% 0.33% 107 min
February 272 70% 0.74% 118 min
March 296 51.5% 1.69% 96 min
April 232 66.4% 1.29% 89 min
May 246 72.4% 2.85% 130 min
June 181 68% 1.66% 99 min
July 260 67.5% 1.92% 71 min
October 72 59.2% 1.39% 111 min
November 140 73.6% 0% 48 min
December 155 61.3% 0% 80 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.