Best time to fly San Juan to Atlanta

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

Best month

June

87.9% on time · 175 flights

Worst month

March

73.6% on time · 229 flights

Month Flights On time Cancelled When late, by
January 195 77.7% 4.62% 126 min
February 177 79.7% 0% 92 min
March 229 73.6% 3.06% 75 min
April 201 74.1% 0% 49 min
May 185 87.4% 0.54% 36 min
June 175 87.9% 0% 67 min
July 207 86.7% 0.97% 71 min
August 156 79.2% 0.64% 68 min
September 128 86.7% 0% 96 min
October 133 82.6% 0% 86 min
November 148 87.6% 1.35% 147 min
December 192 85.3% 3.65% 100 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.