Other facts from our historical weather data: Which is the warmest month in Grövelsjön? July has an average maximum temperature of 18°C (64°F) and is the warmest month of the year. Which is the coldest month in Grövelsjön? The coldest month is February with an average maximum temperature of -4°C (25°F). Which is the wettest month in Grövelsjön? July tops the wettest month list with 99mm (3.9 in) of rainfall. Which is the driest month in Grövelsjön? March is the driest month with 37mm (1.5 in) of precipitation. No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.