usually in the months in key west the average Precipitation is 1 inch. make sure you pack some shorts for the month of august in key west. they have Temperatures reaching over 80 degrees Fahrenheit.
also, keep watch of the high gusts of wind that whip around the island. just to note hurricane season starts july 1st and ends on november 30th. to get out of the gusts key west is warm all year round. If you visit key west you must know what to do if there is a huriccane. in a hurricane watch they can be coming within the area in 36 hours. if told to do something from a citizen follow, they may be saving your life.