May in Bucharest is the rainiest month of the year. In May, the weather in Bucharest is typically warm. Average daily high temperature in May is about 21 degrees above zero. On average, Bucharest has 17 rainy, 11 sunny, and 3 partly cloudy days in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Bucharest.