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 29 degrees above zero. On average, Sihanoukville has 20 rainy, 5 partly cloudy, 4 sunny, and 1 cloudy day 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.