A series of severe thunderstorm watches issued for much of southern Ontario has been lifted by Environment Canada.

As temperatures in southern Ontario hit unseasonably warm highs on Thursday, Environment Canada issued watches stretching from Windsor as far east as Ottawa and Prescott on the Ontario-Quebec border.

In areas including Toronto, Environment Canada warned of the risks are torrential downpours, “toonie size” hail and intense lightning.

A watch means conditions are favourable for storms, as opposed to warnings, when extreme weather is occurring or imminent.

Portions of extreme southwestern Ontario, including Windsor, Leamington and Essex County, were under a tornado watch for part of Thursday evening. That watch was lifted at 7:34 p.m. ET.

Desks were shaking

People in southwestern Ontario reported hail and lightning in the early morning hours of Thursday.

Two men at the Toyota plant in Cambridge felt a tingling in their arms after lightning struck in the parking lot near the spot where they stood.

The men were taken to hospital for observation and are in stable condition.

Kevin Broughton could hear and feel the storm inside the plant.

"The desks in the office were actually shaking with the thunder, so it was pretty severe," he said. "We don't normally see [thunderstorms] this severe this early in the season."

A YouTube video taken Thursday morning in Brantford, located about 100 kilometres southwest of Toronto, shows large balls of hail on the ground.

CBC viewer Pat McKillop reported golf-ball sized hail hitting the ground at 3:45 a.m. in Lucknow, about 125 kilometres north of London, Ont.

"A lightning strike shook me out of my bed as it hit very close by," he said in an email to CBC News. "Then the 'bullets' started, slowly at first then pummelling the house. Unbelievable! This morning, despite the warmth outside, the hail is still there, that is how dense it was."

CBC reporter Charlsie Agro said the Waterloo Fire Department alone got more than 20 calls Thursday morning from people whose homes were damaged by the storms.

One single-car garage and an SUV in Kitchener were destroyed when lightning started a fire in nearby trees.

In southeastern Michigan several houses were damaged and at least two destroyed after a tornado touched down Thursday afternoon.

Unusual spring weather

CBC meteorologist Johanna Wagstaffe said it’s unusual for southern Ontario to see thunderstorms so early in the year.

“It is technically still winter, so this is early, although not completely unheard of, to get thunderstorms this early,” she said. “This setup that we’re looking at in the atmosphere is more April than March-like.”

She said the unseasonably warm weather is likely to continue in southern Ontario for the next two weeks. Normal temperatures for mid-March are in the 5 C range.

“It’s just how long this warm stretch has been going on for and the fact that we don’t really see a break back to seasonal temperatures at least until the end of the month," she said.