Summer in Puerto Vallarta is hot and humid. Expect highs in the upper 80s F/27 C and higher. The heat is often relieved by a rain shower that tends to materialize in the late afternoon or early evening, leaving the better part of the day ideal for beachgoing. June and October can be more uncomfortable than the summer because there is a lesser chance of rain.
Expect nice weather (highs in the upper 60s-upper 70s F/16-21 C) November-April, with rarely any worry of rain. Hurricane season is June-November. December-March is the high season, when the weather is at its best, prices are highest, and the city is most crowded.