Weather will likely play an important role when you plan your trip to Jalpan de Serra, and keep in mind that cheaper options are usually available when the weather isn’t as good. The hottest months are usually May and June with an average temp of 76°F, while the coldest months are January and December with an average of 63°F. The rainiest months in Jalpan de Serra are September, June, October, and July, with each month seeing an average of 8 inches of rainfall.