If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Wasa: The hottest months are usually July and August, with an average temperature of 16°C, while the coldest months are December and February, with an average of -6°C. The snowiest months in Wasa are January, December, February and March, with each month seeing an average of 20 cm of snowfall.