Best time to fly Tulsa to Chicago

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

Best month

September

85.9% on time · 300 flights

Worst month

July

68.8% on time · 356 flights

Month Flights On time Cancelled When late, by
January 269 84% 2.23% 91 min
February 260 82.7% 1.92% 113 min
March 332 79.8% 3.01% 87 min
April 334 83% 2.99% 103 min
May 328 78.8% 0.3% 71 min
June 355 73.8% 2.82% 86 min
July 356 68.8% 1.69% 86 min
August 315 78.8% 0.63% 87 min
September 300 85.9% 0.67% 96 min
October 301 80.7% 0% 63 min
November 300 80.5% 2.67% 93 min
December 317 78.3% 1.26% 81 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.