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Live forecasts update automatically; written guidance last reviewed 16 June 2026 by the Canada Edition Weather Desk. Data from Environment and Climate Change Canada and other national met services via Open-Meteo.
For Toronto, Ottawa, and much of southern Ontario, a weather warning from Environment and Climate Change Canada means hazardous conditions are occurring or imminent. Today’s warnings include winter storm alerts for the Great Lakes region and blowing snow advisories along the St. Lawrence River. Residents should take immediate protective action and monitor Canada weather warnings today for their community.
What is the difference between a weather watch and a warning?
A watch means conditions are favourable for a hazardous event, while a warning indicates the event is happening or highly likely. For example, an ottawa weather warning today for severe thunderstorms means storms are already moving through the capital region. A southern Ontario weather warning today for blizzard conditions means the blizzard has begun, not just possible later. Always treat warnings as immediate calls to action.
How are weather warnings issued in Canada?
Environment and Climate Change Canada meteorologists monitor conditions 24/7 and issue warnings through the public alerting system. Warnings are posted on weather.gc.ca and broadcast via cellphone alerts. In winter, Ontario weather warnings today often focus on lake-effect snow from Georgian Bay or freezing rain in the Ottawa Valley. For summer, see our coverage of fire weather warnings and hurricane alerts. The Toronto Extreme Cold Weather page covers specific winter hazards.
What should I do when a weather warning is issued?
Seek shelter immediately if life-threatening. For winter warnings, postpone travel. For heat warnings, move to cool indoor spaces. Always monitor Environment Canada updates. For a weather warning today in your zone, check the Environment Canada Weather Alerts page.
How often are warnings updated?
Warnings are updated as conditions change, often every hour during active events. Environment Canada issues end statements when the hazard passes. Use canada weather warnings today for real-time changes. For southern Ontario, follow your local forecast.
Does a warning apply to my entire city?
Warnings are issued for specific zones, not whole cities. A weather warning toronto may cover only neighbourhoods near Lake Ontario, while a weather warning ottawa might be limited to rural areas east of the Rideau River. Always check your exact location using Canada’s weather hub or Environment Canada’s map.