The Almanac calls for a milder December in southern Quebec, but MétéoMédia says a mild winter is 'far from a guarantee'

December's average in southern Quebec is forecast at -2°C, about 3°C above normal, with 70 mm of precipitation, roughly 10 mm below average, according to The Old Farmer's Almanac. The Almanac's outlook is for the region as a whole, not Montreal specifically, and it does not say which part gets which weather.

For Dec. 6 to 14 it splits the region: snowy periods in the east and flurries in the west, with temperatures turning cold. Dec. 1 to 5 brings rain and snow showers with mild temperatures. Dec. 15 to 26 brings snowy periods and mild weather again, and Dec. 27 to 31 a mix of rain and snow as temperatures turn cold. The snowiest stretch falls over the holidays. The Almanac says its lower precipitation total does not rule out several good snowfalls.

MétéoMédia's preliminary outlook points the same way for the first half of winter, with the biggest warm anomaly in December. Meteorologist Kevin Cloutier says forecasters are especially confident about the start of the season. The cause, it says, is a "super El Niño," a strong warming of Pacific waters that sends mild Pacific air across Canada and keeps Arctic air near the pole. The setup could also steer storms south of the border, bringing more rain, grey skies and slush than lasting snow to southern Quebec.

André Monette of MétéoMédia says one of the mildest winters on record is possible, especially in December, but calls a mild winter "far from a guarantee." The company's polar vortex update says a disturbance could still bring cold air south in late November or December.

Montreal's mid-winter normals are about -6°C by day and -15°C by night. The city's average first snowfall of 15 cm or more comes around Dec. 23, based on 1991-2020 data. Last year's first big storm hit Nov. 10 with under 20 cm of snow.