August in Grimsi is the warmest month of the year. In August, the weather in Grimsi is typically warm. Average daily high temperature in August is about 10 degrees above zero. On average, Grimsi has 14 rainy, 13 cloudy, and 4 sunny days in August. The rains are usually moderate. August as well as January, February, March, and April is considered the most uncomfortable time to visit Grimsi.