Best time to fly Santa Ana to Chicago

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

Best month

December

84.2% on time · 346 flights

Worst month

June

72.3% on time · 377 flights

Month Flights On time Cancelled When late, by
January 355 79.1% 1.13% 100 min
February 323 82.3% 0% 55 min
March 357 72.8% 0.84% 77 min
April 371 82.2% 0.81% 67 min
May 392 80.4% 0.26% 49 min
June 377 72.3% 0.8% 82 min
July 376 75.8% 0.8% 62 min
August 375 77.1% 1.6% 97 min
September 351 83.1% 0% 53 min
October 374 82.1% 0% 71 min
November 333 81.3% 2.1% 94 min
December 346 84.2% 0.29% 106 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.