Best time to fly Chicago to Jacksonville

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

Best month

April

82.6% on time · 328 flights

Worst month

July

65.6% on time · 307 flights

Month Flights On time Cancelled When late, by
January 279 72.3% 1.79% 64 min
February 264 74.6% 0% 55 min
March 350 74.9% 2% 70 min
April 328 82.6% 1.83% 65 min
May 365 81.5% 0.27% 82 min
June 353 69.7% 2.83% 75 min
July 307 65.6% 1.3% 72 min
August 298 70.4% 2.01% 100 min
September 283 78.3% 0.71% 56 min
October 306 78.9% 0.98% 63 min
November 297 82.3% 1.35% 74 min
December 299 75.3% 0% 75 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.