Record warmth and rain across southern Ontario and Quebec to end the year

The current thaw is making a mess of area roadways. There are plenty of large potholes hidden by deep puddles in some cases. The temperature roller coaster we have been on so far this winter is hard on everything from roads, to homes, cars, animals and even us!

In stark contrast to last Friday in Montreal, today was warm and wet, with record high temperatures established in many locations across Ontario, Quebec, New York and New England. Montreal reached 7.2C (45F) breaking the record at Trudeau Airport of 6.1C (43F) set in 1965. The record from McGill was 7.8C set all the way back in 1889. I managed 9.4C (49F) here on Ile Perrot. Toronto managed 13C (55F) smashing the 1965 record of 7.2C (45F). On Thursday, just one day after 15cm of snow, Ottawa reached 7.5C, breaking the 2018 record of 6.6C.

To our south, Massena and Cornwall reached 11C (52F) surpassing the record of 49F set in 1990. Burlington, Vermont smashed there daily high temperature record, reaching 14C (58F). The old benchmark was 11C (51F) set in 1990. As the day ends, a more complete list of records will show just how warm this airmass is. Keep in mind that the upcoming couple of weeks are typically the coldest of the year in Montreal.

The roller coaster ride is the result of strong low pressure passing well northwest of our region. A surge of warm air has moved north from the southern US. Temperatures will remain very mild overnight, with rain developing as a cold front moves into the region. The low is expected to remain fairly steady around 7C, which would set a record for the warmest overnight low for the date. As is stands, you have to go back to 1884 in Montreal for the previous max low record of 3.9C, so this is quite the event. 

Along with the warm air has been a rapid melting of the snowpack. Montreal had received 63cm of snow this month, most over the last two weeks. As of last evening, 16cm remained on the ground at Trudeau Airport. A large amount has vanished in the warm south winds over the last 36 hours, and most should be gone in Montreal by New Years Day.

In terms of practical weather, expect light rain and fog Friday night into New Years Eve. As the slightly colder air arrives late Saturday night and Sunday, a few flurries are possible. Expect more very warm air on Tuesday and Wednesday, accompanied by rain. Colder weather is expected to return on or about January 6.

The normal high/low for Montreal for late December is -5C/-14C.