If you're hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Las Piedronas: The hottest months are usually March and February with an average temp of 81°F, while the coldest months are January and December with an average of 80°F. The rainiest months in Las Piedronas are September, June, October, and August, with each month seeing an average of 14 inches of rainfall.