If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Tepoztlán: The hottest months are usually April and May, with an average temperature of 21°C, while the coldest months are January and December, with an average of 16°C. The rainiest months in Tepoztlán are September, June, August and July, with each month seeing an average of 258 mm of rainfall.