Get ready, Canada. A strong start to winter is expected across most of the country.

While Canada enjoyed an exceptionally mild fall, a dramatic flip in the jet stream pattern is underway, bringing about an abrupt transition to winter. Will the return of La Niña and a disrupted polar vortex team up to lock in this pattern until spring? Please read on to find out what you can expect during the upcoming winter season.

Before we look ahead, here is a brief reminder of just how mild it was across North America through most of the fall. The various shades of red and orange highlight above-normal temperatures from mid-September through mid-November (see graphic below).

[Winter Forecast: Look back at mild 2025 fall] Winter Forecast: Look back at mild 2025 fall

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