July in Sihanoukville is the rainiest and the cloudiest month of the year. In July, the weather in Sihanoukville is typically hot. Average daily high temperature in July is about 28 degrees above zero. On average, Sihanoukville 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 Sihanoukville.