Environment Canada has confirmed that a tornado touched down in New Tecumseth, Ont., where a roof was torn off a home, causing part of its upper floor to cave in Tuesday afternoon.
The agency said the tornado was likely was an EF-1, at the lower end of the scale, and will be inspecting the damage.
"The winds were between 135 and 175 kilometres per hour," said Dave Phills from Environment Canada.
The path of the tornado may have exceeded ten kilometres in length.
Ontario Provincial Police Const. Paul Nancekivell told CBC News that the storm brought down a handful of trees and power lines along the 15th Sideroad in New Tecumseth, which lies about 90 kilometres northwest of Toronto.
"We've got one residence [that] has been hit here and the roof has been torn off, part of the second floor has caved in," Nancekivell said in a telephone interview.
The back of a garage was also torn off by the storm, he said.
Nancekivell said that some 10 to 15 police cruisers were out in the area, going door to door checking on residents and assessing the damage.
A fire chief told CBC News that a storm had also damaged homes in the Township of Amaranth, about 40 kilometres west of New Tecumseth.
Orangeville fire Chief Andy Macintosh told CBC News that no one was injured to his knowledge.
Macintosh said the damage occurred along the Fourth Line of Amaranth on Tuesday.
The fire chief tweeted photos of downed trees and damaged trunks.
Photos published online by the Orangeville Banner, a local newspaper, showed hydro poles that were blown over.
The Orangeville, Grand Valley and southern Dufferin County areas had been under a severe thunderstorm watch as of late Tuesday afternoon. Amaranth is a part of Dufferin County.
A funnel cloud was also spotted in Essex, Ont., on Tuesday.
The storms on Tuesday came just a week after a tornado struck the town of Angus, Ont., damaging more than 100 homes.