April in Sihanoukville is the hottest month of the year. In April, the weather in Sihanoukville is typically hot. Average daily high temperature in April is about 30 degrees above zero. On average, Sihanoukville has 19 rainy, 6 sunny, 3 partly cloudy, and 2 cloudy days in April. The rains are usually heavy. April as well as May, June, July, and August is considered the most uncomfortable time to visit Sihanoukville.