Heavy rainfall and thunderstorms are expected to hit Toronto and surrounding areas.
A tornado warning has been issued for parts of Niagara Region as a severe thunderstorm moves through that area.
Just before 12:30 p.m., Environment Canada issued the advisory for St. Catharines – Grimsby – Northern Niagara Region, as it tracks a severe thunderstorm that could produce a tornado as well a “damaging winds, large hail and locally intense rainfall.”
“This is a very dangerous and potentially life-threatening situation,” the national weather agency said, urging people to take cover immediately in a basement, interior room, or a sturdy shelter when threatening weather approaches.
If no shelter is available, Environment Canada is advising people lie in a low spot and protect their head from flying debris.
Those who may be out on the water when threatening weather approaches, should return to shore and seek shelter, if possible, or move directly away from the path of the tornado, the agency said.
“Otherwise, wear your lifejacket, lie face down and protect your head,” it advised.
“Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.”
Rainfall warning issued for parts of Niagara
A yellow warning for rainfall was also issued at 3:47 a.m. on Sunday for Niagara Falls – Welland – Southern Niagara Region and St. Catharines – Grimsby – Northern Niagara Region.
Localized heavy rainfall, exceeding 50 mm, is expected in those areas this morning and into the afternoon.
“Locations impacted by multiple thunderstorms are expected to receive rainfall amounts in excess of 50 mm,” the agency said, noting the rain is expected to diminish from west to east later this afternoon.
A person tries to take cover as heavy rains falls in Ottawa, on Wednesday, July 1, 2026. THE CANADIAN PRESS/Keito Newman A person tries to take cover as heavy rains falls in Ottawa, on Wednesday, July 1, 2026. THE CANADIAN PRESS/Keito Newman
Environment Canada says water will likely pool on roads and in low-lying areas and some property damage could occur.
“Don’t drive through flooded roadways. Watch for washouts near rivers, creeks and culverts,” it said.
Special Weather Statement in effect in GTHA
A special weather statement is also in effect for much of the Greater Toronto and Hamilton Area, with periods of rain and thunderstorms expected throughout the day and into the evening.
Just before 6:30 am., Environment Canada issued the advisory the following areas:
Burlington – OakvilleCaledonCity of HamiltonCity of TorontoHalton Hills – MiltonMississauga – BramptonNewmarket – Georgina – Northern York RegionPickering – Oshawa – Southern Durham RegionUxbridge – Beaverton – Northern Durham RegionVaughan – Richmond Hill – Markham
The national weather agency is warning of the possibility of up to 50 mm of localized heavy rainfall starting this morning.
“Periods of rain and embedded thunderstorms are expected through this evening,” it said in the statement.
“Localized heavy rainfall is possible for areas that receive multiple thunderstorms.”
Environment Canada says rainfall warnings may also be issued.
People should note that water will likely pool on roads and in low-lying areas and that visibility will likely suddenly reduced at times.
People make their way through the rain in downtown Ottawa on Monday, June 9, 2025. THE CANADIAN PRESS/Sean Kilpatrick People make their way through the rain in downtown Ottawa on Monday, June 9, 2025. THE CANADIAN PRESS/Sean Kilpatrick
Residents are being urged to visit heir local conservation authority or the Ontario Ministry of Natural Resources for information concerning flooding.
Flooding possible in region
Early Sunday morning, Credit Valley Conservation (CVC) issued a flood outlook statement advising of “localized flash flooding and water pooling on the roads and in flood-prone and low-lying urban areas” in Peel Region.
It noted, however, that flooding of the Credit River and its major tributaries is not expected.
“Urban streams and rivers may be dangerous, especially in the vicinity of culverts, bridges, and dams. People are warned to stay away from all watercourses and to keep children and pets away,” CVC said.
This statement is in effect through Monday or until further notice.
Flood outlook statements are issued as an early notice of the potential for flooding based on weather forecast of heavy rain, snow melt, high wind or other conditions that could lead to high runoff, ice jams, shoreline flooding, or erosion.
Anyone concerned about high water levels in their area should contact their municipality directly or call 911 for emergencies.
Belleville flooding A man walks on a flooded road in Foxboro, Ont., just north of Belleville, on Sunday April 13, 2014. A conservation authority says water flows in the Moira River east of Toronto have reached the same levels as major flooding in 2008, but have stabilized as Belleville residents frantically throw down sandbags and hope for fair weather. (Lars Hagberg/The Canadian Press)
Toronto and Region Conservation Authority is also advising of a “higher potential for flooding” from river system in the region due to the possible significant amounts of rain.
Late Saturday night, it released a Watershed Conditions Statement – Flood Outlook in light of Environment Canada’s issuance of a Special Weather Statement for a weather system that is expected to bring widespread rainfall totals of 20 to 30 mm across TRCA watersheds, with localized rainfall amounts may exceed 50 mm where thunderstorms repeatedly track over the same area.
The conservation authority is noting that the heaviest rainfall in the city is expected between 7 a.m. and 4 p.m. on Sunday.
“Rivers in (our) jurisdiction are likely to rise well above normal water levels, with stronger and faster flows, with the possibility of overflowing. Flooding and water pooling may occur in flood plains and low-lying areas that do not drain well,” TRCA wrote.
“All shorelines, rivers, and streams in TRCA jurisdiction should be considered dangerous as this rainfall may cause rapidly changing water levels and stronger and faster flows in TRCA rivers.”
This statement is in effect until Aug. 3 at noon.
People are advised to stay safe around rivers and riverbanks, shorelines, and nearby trails, paying special attention to keep children and pets away from fast-moving water and consider postponing recreational activities due to these hazards until conditions improve. They should also allow extra time for travel and proceed with caution, never driving, walking, or biking through floodwater, which may be deeper and faster-moving than it looks. Lastly, it is advised to watch for ponding in low-lying areas and underpasses or near storm drains and follow all detour and road closure signage.
To report a flooding incident from a watercourse, leave a message on TRCA’s floodline at 416-661-6514 or if in danger, call 911 immediately.
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