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 Madison: The hottest months are usually July and August, with an average temperature of 21°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in Madison are March, January, April and February, with each month seeing an average of 17 cm of snowfall.