Freeze-thaw events

Currently, there are no studies analyzing historical trends showing the impacts of climate change on freeze-thaw events measured with air temperature.

However, we know that the number of freeze-thaw events varies with seasonal temperatures and that they are being observed more often in the spring and fall in most regions of Quebec. 

During the period from 1981 to 2010, freeze-thaw events were most frequent in the months of October, November, April and May, with the number ranging from 5 to 25 days per month.

In northern Quebec, the number of freeze-thaw days drops to less than 5 per month from November onwards, for the entire winter. In the extreme south of Quebec, they persist until December and start rising in number in March.

Figure: Number of freeze-thaw days in eastern North America (1981-2010)