If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Chignahuapan: The hottest months are usually April and May with an average temp of 61°F, while the coldest months are January and December with an average of 53°F. The rainiest months in Chignahuapan are September, June, August, and July, with each month seeing an average of 9 inches of rainfall.