You'll likely spend much of your trip indoors, but if you want to see more of the area, looking at local weather trends is a good idea. The hottest months are usually April and May with an average temp of 65°F, while the coldest months are January and December with an average of 58°F. The rainiest months in Teotihuacan are August, July, September, and June, with each month seeing an average of 7 inches of rainfall.