July in Mae Sai is the rainiest month of the year. In July, the weather in Mae Sai is typically hot. Average daily high temperature in July is about 29 degrees above zero. On average, Mae Sai has 29 rainy, 1 sunny, and 1 cloudy 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 Mae Sai.