Best time to fly Dallas/Fort Worth to Portland

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

Best month

March

78.3% on time · 186 flights

Worst month

August

49.8% on time · 240 flights

Month Flights On time Cancelled When late, by
January 168 66.7% 8.93% 64 min
February 158 76.6% 1.27% 37 min
March 186 78.3% 1.08% 48 min
April 193 72.3% 1.04% 52 min
May 203 63.1% 3.45% 61 min
June 195 56.8% 5.64% 73 min
July 229 59.2% 2.62% 63 min
August 240 49.8% 2.92% 75 min
September 199 69.9% 1.01% 54 min
October 224 58% 2.23% 79 min
November 202 70.2% 1.98% 73 min
December 213 65.3% 0% 56 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.