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 Vaughan: The hottest months are usually July and August, with an average temperature of 19°C, while the coldest months are February and January, with an average of -3°C. The snowiest months in Vaughan are March, January, February and December, with each month seeing an average of 29 cm of snowfall.