Mild weather to persist well into February for Montreal

A poorly timed snow squall along a frontal boundary made a mess of the evening commute across the western suburbs of Montreal on Tuesday afternoon. Several centimetres of snow quickly covered roads slowing traffic to a crawl on Ile Perrot and in Vaudreuil/Dorion. (Valley Weather Photo)

Special Weather Statement posted for southern Quebec for freezing precipitation late Thursday.

Freezing Rain Warning for the Ottawa Valley.

After the coldest 48 hours in decades, a much warmer weather pattern is becoming established to start the month of February. As I write, the current temperature in Montreal is 5C (41F). It feels like spring outdoors, with warm sunshine and melting snow. This is a far cry from Saturday morning, when Trudeau Airport recorded a record-breaking -29.5C (-21.1F). The previous record low at the airport was -28.9C set in 1963. The McGill record was -30.6C set in 1889. It was the coldest morning in 29 years since the -31.8C reading on January 27, 1994. The windchill was a frosty -44C, also a record for the date.

In contrast to our frigid weekend, January turned out to be one of the warmest on record across southern Quebec. The average temperature in Montreal was the 5th warmest on record for the city at -4.23C (24.4F). Records date back to 1872. The last time a January was this warm was back in 2002.

The arctic air is behind us now, and unlikely to return this winter. Looking ahead to the next 6 to 10 days, we can expect above normal temperatures, with several days well above the freezing point. A warm front Tuesday afternoon produced a brief period of heavy snow right around the evening commute, but it was short-lived. Warmer air has now arrived, with highs close to 5C today under fair skies. Wednesday night will feature clear skies, with mild overnight lows of -5C (23F). 

On Thursday, strengthening low pressure will pass west of Montreal allowing for warm air to remain in place. Temperatures will rise to 4C (39F) by late in the evening. Precipitation will arrive in the afternoon as wet snow, with 2-4cm possible before a transition to rain in the evening. A period of freezing rain is possible during the transition, especially north and east of Montreal and in the Ottawa Valley, where temperatures will be slow to rise above the freezing point. Plain rain will fall in Montreal, with 10-15mm possible. Strong winds are likely on Friday in advance of a trailing cold front, with gusts reaching 70km/h in the St. Lawrence Valley.

Precipitation may briefly change back to snow Friday night before ending by midnight. Saturday will be a fair, seasonably mild day as high pressure builds back into the region. The fair mild weather will be with us most of next week, with an extended period of above freezing temperatures allowing for some of the nearly 95cm of snow that fell on Montreal in January to begin melting.