If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Eau Claire: The hottest months are usually July and August, with an average temperature of 19°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in Eau Claire are March, January, February and April, with each month seeing an average of 20 cm of snowfall.