August in Rovaniemi is the sunniest month of the year. In August, the weather in Rovaniemi is typically warm. Average daily high temperature in August is about 15 degrees above zero. On average, Rovaniemi has 17 rainy, 7 sunny, 6 partly cloudy, and 1 cloudy day in August. The rains are usually moderate. August as well as January, April, May, and June is considered the most uncomfortable time to visit Rovaniemi.