Other facts from our historical weather data: When is the rainy season in Grüsch? Rainy season in Grüsch occurs in the months of May, June, July, August and September. When is winter in Grüsch? The coldest season / winter is in the following months: January, February and December. Which is the warmest month in Grüsch? July has an average maximum temperature of 19°C (66°F) and is the warmest month of the year. Which is the coldest month in Grüsch? The coldest month is January with an average maximum temperature of -1°C (30°F). Which is the wettest month in Grüsch? June tops the wettest month list with 215mm (8.5 in) of rainfall. Which is the driest month in Grüsch? January is the driest month with 113mm (4.4 in) of precipitation. Which is the sunniest month in Grüsch? July is the sunniest month with an average of 192 hours of sunshine. 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.