In July, the weather in San Cristobal de las Casas is typically warm. Average daily high temperature in July is about 22 degrees above zero. On average, San Cristobal de las Casas has 30 rainy and 1 sunny day in July. The rains are usually heavy. July as well as May, June, August, and September is considered the most uncomfortable time to visit San Cristobal de las Casas.