Best time to fly Dallas to Chicago

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

Best month

February

95.6% on time · 91 flights

Worst month

June

62.9% on time · 89 flights

Month Flights On time Cancelled When late, by
January 103 92.9% 3.88% 42 min
February 91 95.6% 0% 68 min
March 116 83% 1.72% 73 min
April 116 73.9% 0.86% 64 min
May 119 64.1% 0.84% 70 min
June 89 62.9% 0% 72 min
July 178 66.7% 0.56% 69 min
August 161 72.5% 0.62% 58 min
September 154 87% 0% 45 min
October 172 80.1% 0.58% 44 min
November 113 90.9% 2.65% 54 min
December 119 83.1% 0% 108 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.