Best time to fly Chicago to Dallas/Fort Worth

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

Best month

August

85.9% on time · 72 flights

Worst month

January

61.3% on time · 33 flights

Month Flights On time Cancelled When late, by
January 33 61.3% 6.06% 83 min
February 39 76.3% 0% 61 min
March 51 67.3% 3.92% 93 min
April 45 69.8% 4.44% 113 min
May 49 68.8% 2.04% 152 min
June 49 62.5% 0% 117 min
July 73 78.6% 4.11% 78 min
August 72 85.9% 0% 79 min
September 73 78.1% 0% 92 min
October 83 77.1% 0% 47 min
November 81 62% 2.47% 92 min
December 47 81.4% 2.13% 172 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.