The Greater Toronto and Hamilton Area is experiencing severe weather, with rain and thunderstorms forecasted for much of the region on Sunday.
Key details:
- localized heavy rainfall possible in much of the GTHA, possibly exceeding 50 mm
- periods of rain was well as thunderstorm expected in region through this evening
- localized rainfall possible in areas that receive multiple thunderstorms
- flooding and water pooling is possible, along with sudden reduced visibility
Follow along for live updates:
Climatologist weighs in on wet weather
Dave Phillips, a climatologist with Environment Canada, chatted with CP24’s Melissa Duggan early Sunday afternoon about today’s intense weather, saying that it’s “hard to get a long weekend in August with every day being perfect.”
“So hey, … having one washout day of three, I don’t think is so bad,” he said.
He did admit that Sunday’s “washout” isn’t ideal, but said at least it isn’t windy.
“(It’s) kind of a really a wet day and not a windy day. It’s not a blowing around, but it’s it really is kind of takes the fun out of being a long weekend in August, for sure,” Phillips said.
Sunday’s wet weather is part of a larger “very moist” system, he explained.
“It’s very loaded with lots of moisture coming from centered on Indiana and then in the Iowa Valley. It’s come through Lake Erie, and we see rainfall warnings for Niagara Peninsula could get up to 50 -plus millimeters of rain in the Toronto area and the GTA and through Kitchener and Durham (and) York region.,” he said, noting that while a special weather statement has been issues for most of the GTHA, that could change if the system stalls and 50 mm of rain falls in an hour or less.
Phillips said Aug. 2 is likely the day each year when the region will see 25 mm of rain or more, adding the good new is that by 4 or 5 p.m. there should be some relief as the moisture seen for most of the day should be “less consistent.”
“We may see a couple of showers lingering tonight, but the drying out is going to begin, and tomorrow looks like an all dry day instead of an all wet day,” he said, adding Tuesday also looks to be a good day.
“It’s going to be nice and more sun than cloud. And that’s clearly going to be the situation come Tuesday.”
Overall, the summer of 2026 has been good weather-wise, the climatologist said, with upwards of 12 days of sun and heat in the region and normal amounts of precipitation.
“If I was going to order the kind of summer for us here, I would order what we’ve had,” he smiled.
“So far it’s not been a washout kind of summer. It’s been good, and you know we still have a month to go. We see August being maybe not kind as warm as July, but comfortable.”
Tornado warning ends in Niagara
A tornado warning that was issued by Environment Canada early Sunday afternoon for St. Catharines - Grimsby - Northern Niagara Region and Niagara Falls - Welland - Southern Niagara Region has ended.
Tornado warning in St. Catharines - Grimsby - Northern Niagara Region
Just before 12:30 p.m., Environment Canada issued a red tornado warning for St. Catharines - Grimsby - Northern Niagara Region and Niagara Falls - Welland - Southern 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.”
Heavy rainfall forecasted in Niagara, Hamilton
A yellow warning for rainfall has also been issued for the City of Hamilton, Niagara Falls - Welland - Southern Niagara Region, and St. Catharines - Grimsby - Northern Niagara Region.
Localized heavy rainfall, exceeding 50 mm, is expected in those areas on Sunday morning and 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.
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 the GTHA
A special weather statement is 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 – Oakville
- Caledon
- City of Hamilton
- City of Toronto
- Halton Hills – Milton
- Mississauga – Brampton
- Newmarket - Georgina - Northern York Region
- Pickering - Oshawa - Southern Durham Region
- Uxbridge - Beaverton - Northern Durham Region
- Vaughan - Richmond Hill – Markham
The statement is no longer in effect for Hamilton.
The national weather agency is warning of the possibility of up to 50 mm of localized heavy rainfall starting Sunday 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.
Residents are being urged to check with their 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.
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.
