Best time to fly Sydney (Mascot) to Perth

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

Best month

May

87% on time · 1,250 flights

Worst month

November

44.9% on time · 872 flights

Month Flights On time Cancelled When late, by
January 1,422 71.2% 0.7% 0 min
February 1,207 69.7% 1.49% 0 min
March 1,309 75.7% 1.38% 0 min
April 1,324 83.5% 0.3% 0 min
May 1,250 87% 0.56% 0 min
June 1,213 75% 1.4% 0 min
July 1,355 69.9% 1.33% 0 min
August 848 53.1% 2.24% 0 min
September 863 66.5% 0.46% 0 min
October 890 57.4% 1.01% 0 min
November 872 44.9% 1.61% 0 min
December 941 64% 0.64% 0 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.