Summer weather is making itself known in southern Ontario, with rising temperatures bringing along the season’s first special air quality statement from Environment Canada.

Hot and sunny conditions in southwestern Ontario and the Greater Toronto Area comes with the possibility of high levels of air pollution Sunday afternoon through Monday, Environment Canada warns.

“Individuals may experience symptoms such as increased coughing, throat irritation, headaches or shortness of breath,” Environment Canada said. “Children, seniors, and those with cardiovascular or lung disease, such as asthma, are especially at risk.”

Environment Canada recommends that people experiencing such symptoms try to reduce or avoid activities outdoors until the warning is lifted. 

The national weather agency also says that a warm air mass is expected to hit southern Ontario on Monday, May 28, with temperatures reaching the low thirties during the day, and overnight lows staying near 20 degrees Celsius.

“These conditions pose a health risk when you are not used to the heat,” Environment Canada said. “Everyone is at risk from heat, especially older adults; infants and young children; and people with chronic illnesses.”