While summer has just officially begun, Quebecers were treated to the first heat wave of the year last week. June 19, 2024 will be a date to remember, with many records shattered. In Montréal, the mercury rose to 33.7°C, eclipsing the 33.1°C mark it hit in 2001. In Québec City, the 2020 high of 33.2°C was surpassed with 33.6°C.  

Although summer in Quebec brings many advantages, like longer days and the return of many outdoor activities, it can also harm people when temperatures get too high. 

The scientific community unanimously agrees on the projected increase in temperatures in Quebec. Heat waves are also a prime example of natural events that are directly linked to climate change. Now more frequent and of higher intensity, they have a direct impact on the health of the population as well as the daily lives of many Quebecers.   

Summer 2024 promises to be hot! 

According to the latest forecasts for the coming summer, it will be one of the hottest we’ve had, says expert meteorologist Réjean Ouimet.     

Already this spring, the month of May was marked by particularly high temperatures. Without talking about a record, Environment and Climate Change Canada points out that the normal maximum temperature for May is usually 18.5°C for Greater Montréal, while this year, a high of 30°C was recorded on May 22, which felt like 37°C with the humidity factored in.   

“You can expect heat,” says Ouimet. “A bit like in previous summers since 2020. The most abnormally warm air will centre on the southern Great Lakes area, but Quebec is close enough to feel some of the effects. As usual, extreme heat is more likely to occur in July and August.” That means we can expect that Quebec will experience other heat waves this summer, like the one we had last week. 

Figure 1 illustrates the seasonal weather forecasts produced by Environment and Climate Change Canada for the summer of 2024 in Quebec. It can be clearly seen that the forecasted temperatures are well above seasonal norms, which suggests several possible heat waves. 

It’s important to be aware that heat can be harmful to health and have significant impacts. It’s essential to prepare and adapt properly. 

How to adapt your activities during periods of extreme heat 

Since many people look forward to summer temperatures, the danger is greater during the first heat waves of the season. When they occur very early in the season, people are still excited about the arrival of warm weather. They’re less alert to signs of impending discomfort and don’t feel the need to make plans to prevent potential impacts on their health.  

When extreme heat occurs as the season is in full swing and people are used to hot weather, they tend to be more vigilant.   

The Institut national de santé publique du Québec (INSPQ) recommends that people adapt their activities to the forecasted weather. In order to protect the public from the dangers of extreme heat, the INSPQ issues specific warnings and disseminates them to the public health departments of the regions concerned. The regions then inform their populations when extreme heat thresholds have been reached and relay prevention messages throughout the heat wave. 

These warnings, which are based on temperature forecasts for the coming days and take the health impacts of heat into account, inform and mobilize health and social services workers when extreme heat is expected. 

Heat and health: What you need to know 

Heat waves, characterized by high temperatures and often accompanied by high humidity, lack of wind, smog or high nighttime temperatures, pose a significant danger to public health. They can cause various physical and mental health problems, and even death.  

It’s important to note that sensitivity to heat is not uniform across the population. Certain groups are more at risk than others due to factors such as age, chronic diseases, certain medications, poor physical condition, obesity, and drug or alcohol abuse.  

There are also social factors associated with heat exposure that must be taken into account, such as social isolation, homelessness, loss of autonomy, reduced mobility, etc.  

All of these factors have direct impacts on the health of Quebecers, as well as indirect impacts. For example, accidents at work can be caused by workers’ reduced concentration in extreme heat. Due to the complexity and diversity of the factors at play, targeted prevention measures are essential to protect the most vulnerable during heat waves. 

Anticipating heat waves allows you to be better prepared 

With the forecasts announced for the coming summer, the population of Quebec should expect this July and August to be punctuated by periods of extreme heat. It’s crucial to stay informed of the expected temperatures in order to prepare properly. 

By learning ways to mitigate harmful effects, taking preventive measures and preparing properly, people can enjoy the summer while being aware of how to avoid the associated health issues.