Other facts from our historical weather data: When is winter in Blue River? The coldest season / winter is in the following months: January, February and December. Which is the warmest month in Blue River? 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 Blue River? The coldest month is January with an average maximum temperature of -2°C (28°F). Which is the wettest month in Blue River? April tops the wettest month list with 81mm (3.2 in) of rainfall. Which is the driest month in Blue River? June is the driest month with 22mm (0.9 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.