Other facts from our historical weather data: Which is the warmest month in Evanton? 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 Evanton? The coldest month is December with an average maximum temperature of 7°C (45°F). Which is the wettest month in Evanton? January tops the wettest month list with 104mm (4.1 in) of rainfall. Which is the driest month in Evanton? April is the driest month with 76mm (3 in) of precipitation. Which is the sunniest month in Evanton? May is the sunniest month with an average of 178 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.