Best time to fly São Paulo to Porto Alegre

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

Best month

October

92.3% on time · 118 flights

Worst month

December

67.7% on time · 527 flights

Month Flights On time Cancelled When late, by
January 525 80.6% 0.95% 43 min
February 463 74.6% 0.43% 40 min
March 547 80.7% 0.37% 39 min
April 1,022 73.3% 1.27% 39 min
May 1,115 81% 0.9% 41 min
June 688 76.4% 1.6% 44 min
July 551 70.8% 0.54% 37 min
October 118 92.3% 0.85% 49 min
November 509 74.8% 0.98% 38 min
December 527 67.7% 1.9% 45 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.