Other facts from our historical weather data: Which is the warmest month in Tärnaby? July has an average maximum temperature of 17°C (63°F) and is the warmest month of the year. Which is the coldest month in Tärnaby? The coldest month is February with an average maximum temperature of -6°C (21°F). Which is the wettest month in Tärnaby? July tops the wettest month list with 108mm (4.3 in) of rainfall. Which is the driest month in Tärnaby? April is the driest month with 61mm (2.4 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.