Environment Canada has issued a special weather statement for Toronto, saying “significant rainfall” is expected this weekend.
The federal weather agency said Friday that local rainfall amounts could total 30 to 60 millimetres and rain could fall at a rate of 40 mm/h.
Rain began Friday evening and is expected to continue through to Sunday.
The weather agency said the heaviest rain is likely to fall on Saturday and higher amounts are possible in certain areas on Saturday afternoon and evening.
“This weather pattern typically brings rapidly changing conditions between sunny skies and heavy downpours,” Environment Canada said.
“Rainfall warnings may be required and issued on short notice to reflect rapidly changing conditions.”
Heavy downpours can lead to flash floods and cause water to pool on roads, it added. Flooding in low-lying areas is also possible.