Environment Canada is tracking a cluster of severe thunderstorms that are predicted to produce extremely strong winds, nickel-sized hail and heavy rain in Ontario.
As of 4:20 p.m., the massive thunderstorm cells travelling 75 km/h, from East Gwillimbury to Bowmanville, then to Dundas and Acton.
The cities that are expected to be most affected include: Milton, Burlington, Brampton, Oakville, Mississauga, Vaughan, Newmarket, Richmond Hill, Toronto, Markham and Pickering.
The large hail and strong winds can easily cause damage and injury, so residents are advised to take extra caution when heading out this evening.
Environment Canada recommends that people take cover immediately, if threatening weather approaches. Lightning kills and injures Canadians every year.
See more details on the severe thunderstorm warning here.