July 18 weather: Wildfire smoke and thunderstorm risk in southern Ontario

Saturday’s forecast calls for showers, more wildfire smoke and a risk of thunderstorms in the Greater Toronto Area and southern Ontario.

Environment Canada says the morning will be cloudy with a 30 per cent chance of showers in the morning in Toronto, Mississauga, Brampton, Hamilton, Oshawa and the Niagara Falls area.

Orange air quality warnings due to ongoing wildfires in northwestern Ontario will stretch into Saturday. The fires have led to evacuations in some communities.

Smoke exposure symptoms include eye, nose and throat irritation, headaches or a mild cough. More serious symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.

A southwest wind blowing around 20 km/h in the morning will gust up to 40 km/h in the morning, with 50 km/h gusts possible in the afternoon.

The afternoon is expected to bring a 70 per cent chance of showers with a risk of thunderstorms, the weather agency says.

The daytime high will be around 26 C in Mississauga but could feel more like 32 C due to the humidity. The UV index will be 6 or “high,” the weather agency says.

Saturday evening will be partly cloudy with a 30 per cent chance of showers in Mississauga. Conditions are again expected to be smokey with wind gusts up to around 50 km/h. The overnight low will be around 16 C, the weather agency says.

Sunday is expected to bring a break from the smoke with sunny conditions in the GTA. The daytime high will be around 24 C before accounting for the humidity, while the overnight low will be around 11 C.