If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Mazatenango: The hottest months are usually March and February with an average temp of 75°F, while the coldest months are January and December with an average of 74°F. The rainiest months in Mazatenango are September, May, June, and October, with each month seeing an average of 22 inches of rainfall.