Environment and Climate Change Canada has placed Toronto and most of southern Ontario under a severe thunderstorm watch as an incoming weather system moves across the region Saturday afternoon.
What forecasters are warning
The federal weather agency is advising that the system could bring wind gusts up to 90 km/h, heavy downpours and hail as large as quarter size in some locations. The watch covers the Greater Toronto Area, Hamilton, Kitchener–Waterloo, Barrie, Peterborough and other communities across the southern part of the province.
“Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, large hail and heavy rain.”
In addition to the watch, meteorologists have already issued a severe thunderstorm warning for some communities — including Orillia and areas north of Belleville — where storms are expected to be most intense.
Potential impacts and local concerns
The main hazards associated with these storms are fast‑moving wind gusts that can reach damaging speeds, intense rainfall leading to ponding and localized flash flooding, and hail that can dent vehicles and damage property. Officials also note that the combination of wind and heavy rain raises the possibility of local utility outages, particularly where trees or branches fall on power lines.
Residents should be prepared for sudden changes in weather and consider securing loose outdoor objects, moving vehicles under cover where possible, and avoiding travel if conditions deteriorate.
Areas under watch and key threats
| Area | Primary threat |
|---|---|
| Greater Toronto Area | Wind gusts up to 90 km/h, heavy rain, quarter‑sized hail |
| Hamilton | Strong gusts, heavy downpours |
| Kitchener–Waterloo | Large hail, heavy rain |
| Barrie | Wind and hail |
| Peterborough | Intense rain, gusty winds |
| Orillia & areas north of Belleville | Severe thunderstorms (warning already issued) |
Practical steps for residents
- Check local alerts: Monitor Environment Canada updates and local media for watches, warnings and storm progress.
- Secure property: Bring in or tie down patio furniture, garbage bins and other loose items that could become projectiles in high winds.
- Power outage preparedness: Gather flashlights, batteries, a battery‑powered radio, and any necessary medications. Keep phones charged and have an alternate charging method available.
- Driving safety: If caught on the road in heavy rain, slow down, use headlights and avoid flooded stretches. Pull over if visibility becomes poor or conditions feel unsafe.
- Avoid sheltering under trees: Strong winds can break branches; seek refuge in a sturdy building if thunder and lightning begin.
Local municipal crews and utility companies monitor severe weather closely. If significant damage or outages occur, expect restoration crews to prioritise safety and critical infrastructure, which can mean variable restoration times for customers.
Why these storms develop in summer
Severe summer thunderstorms across southern Ontario often arise when warm, humid air near the surface meets a cooler or drier air mass aloft, creating instability. Sun‑warmed ground temperatures and available moisture help fuel updrafts, which can organise into strong thunderstorms capable of producing large hail, damaging winds and heavy rain in a short period.
Given the watch and the warnings already in effect for parts of the region, residents should keep an eye on forecast updates and be prepared to move indoors quickly if conditions worsen. Local emergency management offices and Environment and Climate Change Canada remain the best sources for official guidance and real‑time weather information.
Stay safe and follow instructions from local authorities. NEXO RADAR will update this bulletin as new information becomes available.
