While Canadians may look forward to the cozy-sweater weather and beautiful colours of fall, in the back of everyone’s mind is the anticipation (and maybe even dread) of the first snowfall.

Even though people don’t usually have to worry about bringing out their shovels and snowblowers until later in the season, there are times when the snow can catch us off guard.

ALSO READ: Nuclear snow? Seven strange ways humans can change fall weather

Here are three reasons why you might see an early fall snowfall in Canada:

Reason one: Elevation

Canada is far from flat, and elevation plays a big role in temperatures. The higher you are above sea level, the cooler you will be. Sometimes, a few metres can make all of the difference between seeing snowfall near the Niagara Escarpment or not, for example.

This is great for winter sport lovers in Quebec, Ontario’s snowbelt regions, the Rockies, and the vast mountain chains in British Columbia who often see snow falling much earlier than us at ground level.

Reason two: Proximity to water

This one requires a little bit of science. Because air is thinner than water, it can change its temperature rather quickly. In contrast, it takes large bodies of water much longer to cool down in the fall, so typically during this season they are warmer than the land. Because of this, it acts as insulation to lakeside or seaside communities, protecting them from colder air. Therefore, the farther you are from the Great Lakes, Interlake region, or ocean, you could see snowfall earlier than others.

SEE ALSO: How the Great Lakes influence fall and winter weather in Ontario

Reason Three: Latitude

This one is rudimentary, but does play a big role. The farther north you are, you could typically see earlier snowfall. This is because you are closer to the cold, Arctic air that is required for the flakes to fall and to also keep them on the ground.

Of course, this is not the case every time — there are outlier events that are out of the norm. Take Red Deer, Alta., on Aug. 2, 2002 for example — a city around 900 metres above sea level and decently south. But still on this day it snowed, making it one of the earliest snowfall events of Canada’s major cities!

With files from Anika Beaudry.