Published on January 15, 2024 at 10:20 p.m.
A change that is not insignificant. Analysis.
The heart of winter
The heart of winter refers to the coldest time of the year in Quebec. For about forty days, from King's Day to Valentine's Day, Quebec experiences an average temperature that varies between -9°C and -16°C depending on the region. However, a current trend shows a change: this period is getting shorter.
“This period revolves around January 21st, one month after the winter solstice,” explains meteorologist Réjean Ouimet. It is the sun's lowest energy contribution of the year beginning in November that explains this cold. The shift from the time of the solstice is explained by the inertia of the atmosphere (and oceans), which takes a certain time to adjust. However, this period changes depending on the air mass play. »
Heavy trend
Since 2020, winters seem to be following a strong trend: cold periods last less long. In fact, the heart of the season is shorter and gentler than normal. Apart from the year 2022, which was particularly cold, this period of around forty days recorded an average temperature above normal.
“A single heart of winter with many record cold days since 2020,” says Réjean Ouimet. Cold snaps persist in winter under all circumstances. When the heart fails, the beats are shorter but can still be intense. The proof: the absolutely freezing weather on the first weekend of February 2023.”
The cold still exists
A winter without cold is impossible in Quebec. This tendency towards mild seasons does not prevent the polar vortex from expressing itself at least a few times during this forty day period. On average, the province experiences five arctic air waves. These sequences are defined when temperatures of -20°C or lower are recorded for three consecutive days in southern Quebec. Since 2020, Quebec has registered fewer. Again, we have to exclude the winter of 2022, a year in which the heart was colder than normal.
A shortened heart
There have been some very mild winters over the last twenty years. Some of these seasons had something remarkable: a relatively short heart. Last year, only ten days of continuous cold were recorded. However, at the end of the meteorological winter, a late cold snap surprised all of Quebec.