Canada - weather in September

September is the first month of autumn in Canada. In the north it is already cold, while in the south it is a pleasant month.
The average temperatures are already below freezing in the extreme north, where the climate is polar (see Alert), while they are below 10 °C (50 °F) in the vast central-northern areas, where the climate is cold continental (see Inuvik, Yellowknife, Churchill). In the south, September is a very mild month, and the daily average exceeds 15 °C (59 °F) in the warmest cities.
Precipitation (rain or snow) is generally weak in the north, in the Arctic areas, where we are in any case in the wettest period of the year. In the west-central, in the Great Prairies (see Edmonton, Calgary, Regina), where summer is the rainiest season, the rains begin to decrease.
In the extreme west, on the coast of British Columbia (see Vancouver), where summer is the driest season, the rains begin to increase, although they are still moderate.
In the extreme south, in the Great Lakes area (see Toronto), in Québec (see Montreal, Ottawa), but also in the east, on the Atlantic coasts (in New Brunswick, Nova Scotia and Newfoundland, see Saint John's, Halifax), the rains are frequent, as in the rest of the year.
In September, and sometimes even in October, there can still be a period of summer-like weather, called Indian summer.
On the other hand, the first cold air irruptions can bring the night temperature to around 5 °C (41 °F) even in the south.
From mid-September to mid-October, from north to south, after the first cold (but not freezing) nights, especially in the eastern provinces (Ontario, Québec), the trees take on autumn colors (fall foliage), which are often more intense and spectacular than in Europe.
Every now and then, Nova Scotia (see Halifax) and the island of Newfoundland can be reached by hurricanes from the Atlantic Ocean, which bend towards the north-east after affecting the Caribbean. They usually arrive weakened because they have to cross a cold sea, however, they can still bring heavy rains and strong winds.
On both coasts, the sea is cold for swimming.




See also: Canada, the weather in August - October
The climate of Canada