Other facts from our historical weather data: Which is the warmest month in Ylläsjärvi? July has an average maximum temperature of 20°C (68°F) and is the warmest month of the year. Which is the coldest month in Ylläsjärvi? The coldest month is January with an average maximum temperature of -7°C (19°F). Which is the wettest month in Ylläsjärvi? July tops the wettest month list with 96mm (3.8 in) of rainfall. Which is the driest month in Ylläsjärvi? March is the driest month with 36mm (1.4 in) of precipitation. Which is the sunniest month in Ylläsjärvi? June is the sunniest month with an average of 278 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.