Best time to fly São Paulo to Rio de Janeiro

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

Best month

February

87.3% on time · 105 flights

Worst month

December

71.1% on time · 117 flights

Month Flights On time Cancelled When late, by
January 114 86.6% 1.75% 58 min
February 105 87.3% 2.86% 34 min
March 124 86.3% 0% 51 min
April 237 82.5% 1.27% 43 min
May 247 83.9% 2.02% 46 min
June 149 86.4% 1.34% 46 min
July 155 76.2% 2.58% 37 min
October 31 87.1% 0% 41 min
November 118 87.3% 0% 36 min
December 117 71.1% 2.56% 47 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.