Best time to fly São Paulo to Curitiba

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

Best month

October

87.5% on time · 72 flights

Worst month

December

60.5% on time · 435 flights

Month Flights On time Cancelled When late, by
January 442 69% 1.58% 43 min
February 359 72.9% 1.39% 44 min
March 425 79.5% 0.24% 44 min
April 782 72.7% 1.79% 37 min
May 841 80.5% 1.07% 37 min
June 531 79.8% 2.07% 34 min
July 399 70.5% 0.75% 32 min
October 72 87.5% 0% 39 min
November 403 78% 1.99% 35 min
December 435 60.5% 3.45% 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.