It feels like June. However, it is the end of September. A month that was hotter and drier than seasonal, Environment Canada summarizes. In the parks and rivers of the metropolis, the sun brings joy to young and old on this last day of September.
Published at 7:30 p.m.
“It’s really a gift, today and even all week,” says François happily, returning from a trip to Mount Royal with his partner Jean.
PHOTO JOSIE DESMARAIS, THE PRESS
François and Jean met in Jeanne-Mance Park
People stroll around him in Jeanne Mance Park. Some sunbathe in swimsuits. Guitar sounds resonate. The smell of barbecues creeps in. The sun floods the flower bed through the leaves of the trees that are just beginning to change color. On the Lachine Canal, passers-by on paddleboards meet families fishing.
The mercury reached a comfortable 23°C in Montreal on Saturday. In the coming days, as October begins, temperatures are expected to reach 26°C before falling again towards the end of the week.
This month of September was on average 2 to 3 degrees warmer than seasonal norms, explains Dominic Martel, meteorologist with Environment Canada. This difference was particularly pronounced in Montreal, with an average of 18.5 °C, compared to the seasonal normal of 15.5 °C.
All of Quebec experienced a similar scenario, specifies the meteorologist. In Trois-Rivieres, where the normal temperature is 14°C, we observed 16.3°C. On the Quebec side, the mercury averaged 16.2°C, compared to 12.7°C normally. In Saguenay the normal temperature is 12°C, we observed 15.4°C. In Mont-Joli the average temperature was 15°C, compared to the usual 12°C. And 14.6°C in Gaspé, as opposed to 11.5°C in normal times.
Not to mention, rainfall was below normal in most parts of Quebec, with the exception of the east. This is particularly evident in Montreal, where only 27 mm of rain was recorded, compared to 83 mm normally in September. A rain deficit of 68%.
“We have to stay vigilant”
This succession of good weather should not make us lose sight of the risks associated with climate change, says Philippe Gachon, professor of hydroclimatology at the geography department at the University of Quebec in Montreal (UQAM).
“We just had the hottest summer ever recorded in Canada,” he remembers. Especially in the north, there is a risk that the month of September will end with three or even four consecutive months of warmer temperatures. [que les normales]. It’s unique, it’s extraordinary. And that’s a bit like what’s happening around the world. »
In fact, Agence France-Presse reported on Friday that the month of September was the hottest ever recorded in France, Germany, Poland and even Switzerland.
However, the expected impacts of climate change include periods of heavy rainfall followed by droughts, Mr Gachon recalls.
“Currently, the North Atlantic continues to be much warmer than usual,” he notes. This means more humidity and low pressure systems moving slower than usual. » Result: Storms that suddenly stay in the same place and cause more precipitation.
The professor illustrates how the rain that fell on New York on Friday flooded the streets and paralyzed part of the subway system.
Despite everything, it’s worth celebrating the dry weather this fall in Quebec: The rainy summer caused lake and river levels to rise and the soil to become saturated. “The month of September left everything a little dry,” recognizes Mr. Gachon. And that limited the risk of flooding. » Nevertheless, in his opinion, autumn is just beginning. “We have to remain vigilant. »
Impact on fall foliage?
A warmer and drier autumn can, in certain cases, delay the appearance of autumn colors, also confirms Michel Labrecque, head of the Botanical Garden’s research department.
Although it is primarily the reduction in sunshine duration that influences the cessation of photosynthesis production in trees, temperature can also play a role.
“If it is very hot, it can slow down the process and cause the autumn colors to appear later,” explains the researcher. “What we’re seeing this year, particularly in southern Quebec, is that the fall colors are appearing a little earlier than we would normally see. »
According to Bonjour Québec’s interactive map to help you track fall colors, most regions along the St. Lawrence River are just beginning the process as of Sept. 28. The color season runs from September 15th to October 15th.
Drought can also cause leaves to fall before they change color, Mr. Labrecque adds. “Luckily we had a very, very wet summer,” he says. We are not in a catastrophic situation. We can all enjoy the beautiful weather and the spectacle of colors. »