Coldest air of the season set to move into southern Quebec

We had more snow again this week in Montreal. So far this January, between 20 and 30cm of fresh snow has fallen across the metro region. We have had at least a trace of snow measured each day this month through January 16, with the exception of Friday, January 10. (Valley Weather Photo)

An arctic airmass will invade southern Quebec late this upcoming weekend, ushering in the coldest air so far this season, and likely colder than anything we experienced last winter.

Temperatures were very mild during the winter of 2023-2024, with no readings below -18C (0F) for the entire season in Montreal. So far this winter, I managed to just sneak below the -18C threshold at my home on Ile Perrot, down to -18.3C (-1F) on December 26. In general you need to go back to February 2023 for the last significant cold snap in the city. Montreal dropped to -29.3C (-21F) on February 4. That brief cold spell closed schools and strained Hydro resources for a day or two.

The upcoming arctic weather will not be that drastic, but will certainly feel much colder than most of us are accustomed to with the recent warmer-than-normal winters.

Before the cold air arrives, we are looking at yet another clipper system Thursday, that will be responsible for some nuisance snow, perhaps a dusting to 1cm. The flurries will end Thursday night, with partly cloudy skies expected on Friday. Expect very mild temperatures, with highs between 0C and -3C (27 to 32F) through Saturday and lows not falling far from those readings.

On Saturday, low pressure passing well north of Montreal will give us a shot of mild air on gusty south winds just in advance of a strong cold front. That front will cross the region late Saturday, accompanied by snow and gusty winds. Another front arrives late Sunday, with light snow and a reinforcing shot of cold air. By Monday, highs will struggle into the minus teens, with overnight lows through Wednesday morning colder than -20C (-4F) in Montreal. Windchill readings will drop into the minus 30s.

Arctic high pressure will settle over southern Quebec on Monday, with clear and frigid conditions forecast.

I will post further updates as the details become a little more clear. Plan for some very cold temperatures, dangerous windchills and more snow through the end of this month.