Puerto Vallarta or Vallarta as it is known by the locals is celebrated for its great sunny climate all through the year. It is very popular amongst North Americans escaping from the winter gloom and freezing temperatures in favor of guaranteed pleasant, sunny weather.
A tropical savanna climate, Puerto Vallarta has wet summers and dry winters, which is a great combination as it never gets too hot nor too cold. The average temperatures quoted for Puerto Vallarta are highs of 91ºF (33ºC) and lows of 61ºF (16ºC) with temperatures seldom falling under 57ºC (14ºC) or soaring above 93ºF (34ºC). Sounds perfect, doesn’t it?
For many, the best times to visit Puerto Vallarta are during the dry winters or from November to February, especially as you can guarantee sunshine, while during the summer months the ocean is warm and the tropical thunderstorms at night are magical. The good thing about rain in Puerto Vallarta is that it rarely stays wet all day, and showers are usually heavy and short lived, meaning you will get plenty of sunshine during a vacation during the rainy season.
Reference: http://weatherspark.com/averages/32587/Puerto-Vallarta-Jalisco-Mexico (retrieved 09.27.13)