If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Chantepec: The hottest months are usually May and April with an average temp of 74°F, while the coldest months are January and December with an average of 65°F. The rainiest months in Chantepec are July, August, September, and June, with each month seeing an average of 7 inches of rainfall.