Ontario sees air quality 'deteriorating' warning on hot and sunny day

A special air quality statement has been issued in Ontario due to unseasonal hot and sunny conditions on Friday afternoon.

Environment Canada warned residents of “deteriorating air quality” increasing ground-level ozone concentrations as temperatures soar into the high 20s.

Toronto hit 29 C on Thursday, breaking the previous record of 27.1 C set on April 13, 1977. On Friday, a 26 C high is forecast in Toronto.

The national weather agency’s warning spans most of southern Ontario, including the Greater Toronto Area, Hamilton, Windsor, London and Niagara Falls.

Symptoms such as increased coughing, throat irritation, headaches or shortness of breath may result from the conditions, the agency says.

“This is not a great threat to the general population,” CP24 meteorologist Bill Coulter said Thursday, highlighting that those with respiratory issues face an increased risk.

“No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation,” Coulter added.

In addition, Environment Canada said extra caution is warranted for residents with heart problems or diabetes, along with children and the elderly.

Over the weekend, temperatures are expected to return to the low 20s, with 22 C expected on Saturday and 21 C set for Sunday in Toronto.

An unwelcome return to damp weather is on tap for next week with The Weather Network projecting rain on Monday and Tuesday in the Greater Toronto Area will transition to light snow.

Temperatures are forecast to drop down to the low 10 C mark for the rest of the month.

With files from Phil Tsekouras.