Best time to fly San Francisco to Dallas/Fort Worth

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

Best month

September

83.1% on time · 634 flights

Worst month

June

65.8% on time · 785 flights

Month Flights On time Cancelled When late, by
January 634 80.2% 7.1% 121 min
February 582 83% 0.69% 120 min
March 680 75.8% 1.62% 110 min
April 684 72.1% 1.17% 94 min
May 767 71.3% 2.87% 68 min
June 785 65.8% 2.93% 89 min
July 755 71.8% 1.99% 74 min
August 710 72% 1.41% 78 min
September 634 83.1% 0.79% 69 min
October 724 83.1% 0.97% 74 min
November 664 74.2% 1.2% 71 min
December 670 77.8% 1.49% 76 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.