April in Bangkok is the hottest month of the year. In April, the weather in Bangkok is typically hot. Average daily high temperature in April is about 36 degrees above zero. On average, Bangkok has 13 rainy, 9 sunny, 7 partly cloudy, 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 Bangkok.