In May, the weather in Härnösand is typically warm. Average daily high temperature in May is about 11 degrees above zero. On average, Härnösand has 11 rainy, 9 sunny, 7 partly cloudy, and 4 cloudy days in May. The rains are usually light. May as well as March, April, September, and October is considered the most uncomfortable time to visit Härnösand.