Best time to fly Dallas/Fort Worth to Chicago

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

Best month

February

84.6% on time · 39 flights

Worst month

March

59.2% on time · 51 flights

Month Flights On time Cancelled When late, by
January 33 71% 6.06% 183 min
February 39 84.6% 0% 106 min
March 51 59.2% 3.92% 83 min
April 45 67.4% 4.44% 104 min
May 49 66.7% 2.04% 112 min
June 49 69.4% 0% 104 min
July 73 71% 5.48% 56 min
August 72 80% 1.39% 75 min
September 71 84.5% 0% 116 min
October 83 76.8% 1.2% 56 min
November 81 66.7% 2.47% 114 min
December 47 68.9% 4.26% 123 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.