Hot damn! July one of hottest on record
This July was the hottest the island of Montreal has experienced in nearly 100 years.
The month’s average temperature of 24.2 C fell just half a degree shy of the all-time high of 24.7 C, recorded 97 years ago in 1921.
“It’s not a record-breaking month, but it’s close to the maximum ever recorded in Montreal,” said Environment Canada meteorologist Simon Legault. “We can definitely say we’re in the Top 3 in the Montreal area.”
The 2018 average is also three degrees above the mean July temperature of 21.2 C.
From day to day, a three-degree increase might not seem like a lot, but over a month, Legault said, it makes a difference. He explained that means monthly temperatures tend to vary by one degree year to year, so a difference of three degrees is “way (above) normal for a month-long period.”
Dominique Paquin, a climate simulation and analysis specialist with research consortium Ouranos, said it’s too early to definitively attribute the waves of extreme heat that spread across the northern hemisphere in July to climate change, “but we know that with climate change, the number of days with extreme heat will increase.”
“We can’t formally attribute it to climate change based on statistics,” she said, “but it’s clear that it gives us a look at what will become the norm.”
In efforts to mitigate the effects of extreme heat, Paquin said new regulations are being implemented across Quebec to combat heat islands, which are described by the city of Montreal as spaces that absorb and store heat, including parking lots and flat rooftops. Increased green spaces and green infrastructure are crucial, she said.
And that is not lost on the city. In its 2015-2020 Climate Change Adaptation Plan for the Agglomeration of Montreal, the city said that heat islands cover 28 per cent of the island, making it particularly susceptible to extreme heat.
One measure the city hopes to implement as part of the action plan is a regulation that dictates the ratio of green to built spaces in the city. How the plan has progressed since it was announced in 2015 is unclear.
While it’s too early to predict what August will be like as a whole, Legault said it is shaping up to be around the norm — despite starting with a short hot spell this weekend. Unlike the early-July extreme heat that is reported to have caused the deaths of 54 Montrealers, Legault expects the upcoming heat wave to be “normal,” with temperatures at or slightly above 30 C and with milder humidity.
The level of humidity and how long the high temperatures last are the biggest differences between normal and extreme heat waves, Legault explained. We also tend to become acclimated to new norms, he said, so while it will be hot, it might not feel as bad compared to what July put us through.