May in Penang is the hottest month of the year. In May, the weather in Penang is typically hot. Average daily high temperature in May is about 30 degrees above zero. On average, Penang has 27 rainy, 2 cloudy, 1 sunny, and 1 partly cloudy day in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Penang.