July in Phnom Penh is the rainiest and the cloudiest month of the year. In July, the weather in Phnom Penh is typically hot. Average daily high temperature in July is about 30 degrees above zero. On average, Phnom Penh has 31 rainy days in July. The rains are usually heavy. July as well as April, May, June, and August is considered the most uncomfortable time to visit Phnom Penh.