Extreme cold and cold warnings
Get cold warnings and weather alerts:
- directly through our mobile app WeatherCAN
- on your desktop at Canada.ca/weather
About extreme cold
Even normal winter temperatures in Canada can be harmful, especially for those at-risk. Canadians can use our weather forecasting products to know how cold it is or set up custom Temperature Notifications using the WeatherCAN App.
Extreme cold events happen when:
- temperatures are lower than usual for your local climate
- there are very low wind chill values and
- there is a risk of frostbite
Extremely cold temperatures can be hazardous even if there is little or no wind.
Cold warnings
We use cold warnings to let you know when the temperature or wind chill is much colder than normal and is likely to affect your health.
We define cold warnings using specific weather impact levels based on temperature and wind chill.
Our weather alerts share the impact the weather could have on you, and what weather conditions you can expect to see.
When we issue cold warnings
We issue cold warnings:
- when significant cold temperatures or wind chills are expected to occur
- at different temperatures depending on where you live
- when you may need to pay extra attention and take action to stay safe
Parts of a cold warning
A cold warning weather alert lets you know:
- the type of alert (i.e.: Cold warning)
- the length of the weather system: the beginning and expected end of the extreme cold event (i.e.: From: Now, To: Friday May 8, 11:00 am PST)
- how the cold can affect you
- how the cold will impact you and your community
- who is at higher risk and how the cold can affect them
- potential risks and effects to your health
- how to keep yourself safe
- steps to protect your health and those at risk from the cold
- description of the weather
- temperature levels, potential wind chill, etc.
Extreme cold and wind chill
We use the wind chill to measure how cold the weather and wind speed together will feel on your skin. You can use the wind chill calculator or check out your risk for wind chill exposure to ensure you’re staying safe during cold weather events.
Wind chill in the forecast
We include wind chill in the forecast when temperatures are below zero and wind speeds are 5 km/h or greater.
We do not issue wind chill warnings. We only issue cold warnings, which include wind chill as part of the forecast.
Learn more about wind chill.
How to keep safe in cold weather
Even though we issue warnings when winter temperatures drop much lower than normal, you can still get a cold-related injury at moderately cold or near-freezing (0°C) temperatures, even with little or no wind. Stay aware of the hazards and learn what you can do to lower your risk:
- take steps to reduce your risk of cold weather injury before going outdoors
- cold weather injuries can include windburn, frostbite, hypothermia, and heart attack
- certain groups of people are at higher risk for cold injury
- prepare for extreme cold events before, during, and after to keep safe
- learn how to treat cold weather injuries
- keep safe from other cold season weather hazards
Keep in mind, it is important to take precautions to protect your health when temperatures are cool, even if there is no cold warning in effect.
Our role in extreme cold
Environment and Climate Change Canada shares information and helps public health and emergency officials across Canada protect people from the effects of cold temperatures.
Our goal is to:
- give you as much advance notice as possible about potentially hazardous weather
- help you understand how the weather may impact you
We issue warnings, watches, and special statements with our weather alerts to help you take steps to protect yourself and your property from harm.
We also issue special mariner alerts to warn of hazardous marine weather, ice conditions, or icebergs that could threaten their safety.