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 GIG record →

Best month

October

80% on time · 35 flights

Worst month

December

64.2% on time · 408 flights

Month Flights On time Cancelled When late, by
January 402 68.4% 0.75% 46 min
February 363 68.1% 0.55% 41 min
March 395 77.7% 0.25% 34 min
April 709 71.4% 0.99% 41 min
May 826 78.9% 0.24% 34 min
June 479 79.5% 1.25% 34 min
July 347 75.1% 0.29% 35 min
October 35 80% 0% 39 min
November 389 75.3% 1.29% 30 min
December 408 64.2% 2.21% 52 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.