The climate of Collingwood is humid continental. The town is located in the snow belt region and receives modest amounts of both snow and rain through the year.

In the spring months there is a gradual warming due to the proximity of Georgian Bay. Frequent shower pass over the region this time of year and later on in the season can turn into severe storms. Temperatures this time of year range from −5 °C to 22 °C.

In the summer months, there are warm to hot humid conditions with frequent lake breezes to cool things off. Thunderstorms are regular occurrences in the summer and can sometimes be severe enough to cause tornadoes. Temperatures this time of year can range from 11 °C to 26 °C. The humidity will often make it feel much hotter than the actual temperature and can even make it feel like the mid 40 °C.

Winter is a very cloudy and cool wet time of year with frequent wind and frosts. Sometimes winter thaws will occur and the town may go multiple days above the freezing mark melting much of the snow. This will usually happen when a strong storm is approaching from the west.