False fall front: Canadians could potentially see one, last burst of summer

A sunset in Valois Bay, Wednesday, Sept. 10, 2025. (Gerry Zampini)

Canadians have been feeling the September chill coming through, but there may still be time yet for the coats to be unpacked.

A cold front has been spreading across Canada, but according to one expert there may be a few more warm days left in 2025.

This brief cold snap is a typical weather pattern, before a brief return of sunny days said CTV News’ meteorologist Kelsey McEwen.

McEwan called it an “old fashioned tug of war between seasons,” and said it’s neither unusual, nor climate change.

Ontario and Quebec have been feeling especially cool this season, McEwen said.

“We had large areas of low pressure higher up in the atmosphere that were propagating through, or moving through our area,” she said.

McEwen said that the jet stream - the source of the cold, would move briefly move south, giving colder air a chance to clear out.

The cold air usually heads north, up to the northern prairies and the territories, through Hudson’s Bay. As the jet stream moves north, more sunny days can be expected, McEwen said.

She said that the cold stream will move through Windsor, towards Ottawa, then Montreal, and Quebec City.

After seeing lows of up to 18 C, Canadians can expect warmer days to make a comeback, with temperatures rising to 26 C-27 C next week, accoridng to McEwen.

She called it the “last gasp of summer a penultimate moment.”

‘A real transition season’

For communities north of Lake Superior the contrast can be felt even more strongly, McEwan added. The cold can be felt in those places, where frost advisories have become “almost regular.”

The clear skies open the door for bright, sunny days but chilly frost bitten nights, McEwen said.

“That clear sky overnight (is) almost like you lose your blankets while you’re sleeping, leading to frost overnight,” she said.

She called fall “a real transition season,” because “meteorologically speaking, so much can change.”

Meanwhile, on Friday, much of Alberta and Saskatchewan sat comfortably in the 20s, along with south east and north west Ontario.

A week ahead, Sept. 19 shows those warm patches dropping off, with most of the interior of the country and the southern parts of the Maritimes having temperatures between 10 and 20 C, according to Natural Resources Canada.