Best time to fly Austin to Chicago

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

Best month

May

79.1% on time · 298 flights

Worst month

March

64.5% on time · 302 flights

Month Flights On time Cancelled When late, by
January 207 71.8% 5.31% 97 min
February 214 79% 0% 65 min
March 302 64.5% 4.64% 107 min
April 294 69.8% 3.4% 108 min
May 298 79.1% 0% 74 min
June 269 68.3% 1.86% 109 min
July 268 66.7% 2.99% 82 min
August 266 74.8% 3.01% 64 min
September 258 77.4% 0.39% 60 min
October 298 71.7% 0.34% 82 min
November 254 70% 3.54% 103 min
December 238 72.6% 0.42% 104 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.