Best time to fly Chicago to Santa Ana

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

Best month

May

87.7% on time · 391 flights

Worst month

July

74.1% on time · 376 flights

Month Flights On time Cancelled When late, by
January 354 77.6% 1.13% 51 min
February 323 76.9% 0% 44 min
March 358 78% 0.84% 58 min
April 371 77.2% 0.54% 52 min
May 391 87.7% 0.26% 45 min
June 378 75.4% 1.06% 57 min
July 376 74.1% 0.8% 62 min
August 374 76% 1.07% 49 min
September 352 77.8% 0% 44 min
October 374 78.6% 0% 53 min
November 332 82.8% 1.81% 68 min
December 347 81.2% 0.29% 56 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.