A severe thunderstorm watch has ended for parts of southern Ontario as storms with the potential for nickel-sized hail and 100 km/h winds moved through the region on Wednesday.

Environment Canada issued weather watches for Toronto, York Region, Durham Region, Niagara, Halton Region and Hamilton, warning residents that that these areas could see damaging wind gusts of up to 100 km/h, along with large hail.

In other areas of the province, including Barrie and London, tornado watches were issued.

The weather agency projected the timing they expect the storm to hit in various parts of southern Ontario on their estimated arrival map.

"The main hazard will be damaging wind gusts. There is some uncertainty as to how far east the risk of severe weather will continue this evening," the weather agency said.

"Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles."

At around 10:40 p.m., the agency lifted its watch for Toronto and a number of other areas.

The storm warnings landed on the second day of a heat warning in southern Ontario.

The warning began on Tuesday and stretches across most of the province.

Temperatures in Toronto reached above 30 degrees Celsius on Wednesday, but felt more like 40 degrees with the humidity.

The city's average high in mid-July typically hovers around 27 degrees. At night, the low will only drop down to 21 degrees, providing little relief from the heat.

Slightly cooler, more seasonal temperatures are set for Thursday. Environment Canada is projecting 27 degrees, with a humidex of 35.

Senior Climatologist for Environment Canada Dave Phillips calls these the "dog days of summer."

"This is the time where you'd expect those roasting, blistering temperatures," he told CTV News Channel on Wednesday. "What’s different about this particular period is the duration."

In the meantime, the weather agency warns that this hot and humid weather can deteriorate air quality. They are asking people to watch out for the following signs of a heat-related illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.

"Seek a cool place such as a tree-shaded area, swimming pool, shower or bath, or air-conditioned spot like a public building," Environment Canada says.

"Never leave people or pets inside a parked vehicle."

The city has extended the hours at seven public pools until 11:45 p.m. for a second day.

The facilities that will be open late include: Alex Duff, Giovanni Caboto, McGregor Park, Monarch Park, Parkway Forest, Smithfield and Sunnyside – Gus Ryder.