Summer is the rainy season throughout much of Mexico.
Winters are comparatively dry.
The higher the elevation, the cooler and less humid the air. Winter storms sweeping down from the north can affect weather as far south as Cancun, and Puerto Vallarta Mexico's East Coast is wetter than the West Coast. Southern Mexico is generally rainier than the north. Mexico's entire coastal areas are subject to high levels of humidity from July through October. The most consistently balmy weather can be found on the Pacific Coast from Manzanillo to the Guatemalan border.