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Weather Guides & Safety Resources

Expert Canadian weather guides, seasonal survival checklists, and emergency safety resources.

Featured Guides

How to Read a Canadian Weather Forecast
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How to Read a Canadian Weather Forecast

Environment Canada's weather forecasts contain a lot of information. This guide explains every element — from probability of precipitation to wind chill values — so you can make informed decisions.

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Winter Storm Safety: A Complete Canadian Guide
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Winter Storm Safety: A Complete Canadian Guide

Blizzards, freezing rain, and extreme cold are facts of life in Canada. This comprehensive safety guide covers how to prepare before, stay safe during, and recover after winter's worst.

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Canadian Weather Glossary: A-Z of Weather Terms and Definitions
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Canadian Weather Glossary: A-Z of Weather Terms and Definitions

From Air Mass to Zenith Angle, this comprehensive glossary defines the weather terms used by Environment Canada meteorologists and weather professionals across Canada.

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Safety Checklists & Information

Winter Storm Safety: A Complete Canadian Guide

Safety Guide

Flood Safety Guide for Canadian Homeowners and Communities

Safety Guide

Extreme Heat Waves Safety Guide

Safety Guide

Wildfire Evacuation Safety: What to Do When Fire Threatens Your Community

Safety Guide

How to Build a Safe Emergency Kit for Your Car

Safety Guide

Wildfire Smoke and Air Quality Guide: How to Interpret AQI/AQHI in Canada

Safety Guide

How-To Tutorials & Instructions

How to Read a Canadian Weather Forecast

Environment Canada's weather forecasts contain a lot of information. This guide explains every element — from probability of precipitation to wind chill values — so you can make informed decisions.

How to Prepare for a Winter Storm in Canada

Winter storms can be extremely dangerous. Learn step-by-step how to protect your family, secure your home, and winterize your supplies.

How to Winterize Your Home for a Canadian Winter

A Canadian winter can be brutal on your home. This step-by-step guide covers everything from insulating pipes to cleaning gutters before freeze-up.

How to Create a Family Emergency Weather Plan

When severe weather strikes, having a pre-made family emergency plan can save lives. This guide walks you through creating a plan tailored to the weather risks in your specific region of Canada.

How to Protect Your Home from Spring Flooding and Sewer Backups

Spring snowmelt and heavy rains create major flood risks for Canadian homes. Learn how to safeguard your property.

Seasonal Tips & Forecasts

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Canada's Spring Weather: Regional Guide and Seasonal Tips

Seasonal Guide
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Summer Weather in Canada: Regional Guide from Monsoons to Midnight Sun

Seasonal Guide
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Preparing for Canada's Ice Storm Season

Seasonal Guide
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A Guide to Spring Gardening Weather in Canada

Seasonal Guide

FAQ - Common Questions

A Special Weather Statement (SWS) is issued when weather is significant but doesn't meet criteria for a watch, advisory, or warning. It may be issued for a long period of wet weather, a brief period of heavy rain, or significant conditions that are difficult to predict with certainty. Action: Be aware and monitor the situation.
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An advisory is issued when weather conditions may be hazardous — causing minor inconvenience or difficulty for some activities — but don't meet warning criteria. Examples include freezing drizzle advisory, blowing snow advisory, or a fog advisory. Action: Use caution. Delay or cancel activities if possible.
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A watch is issued when conditions are favourable for the development of severe weather and the event is likely (usually within 6-24 hours). Watches are issued for potential tornadoes, severe thunderstorms, blizzards, and similar events. Action: Prepare. Know where you will take shelter. Monitor updated forecasts closely.
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A warning is the most urgent alert level. It means severe, dangerous weather is occurring or imminent. Warnings are issued for tornadoes, severe thunderstorms (with large hail or damaging wind gusts), winter storms, wind, rainfall, freezing rain, blizzard, and extreme cold. Action: Take action immediately. Implement your safety plan.
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A tornado warning is issued when a tornado has been spotted by a trained spotter or detected on Doppler radar. This is a life-threatening emergency. If a tornado warning is issued for your area, take shelter in the lowest floor of a sturdy building immediately, away from windows. Do not wait to see the tornado before acting.
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Wireless Emergency Alerts (WEA) are notifications sent directly to cellphones within range of cellular towers in a designated geographic area. They are reserved for the most extreme, life-threatening situations including tornado warnings, extreme weather alerts, and Amber Alerts. When your phone receives a WEA, it emits a distinctive loud alarm sound. Take these seriously and take immediate action.
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A weather watch is issued when atmospheric conditions are favorable for the development of severe weather. A weather warning is issued when severe weather (such as a tornado, blizzard, or heat wave) is imminent or already occurring in your area. Take immediate action when a warning is active.
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The Humidex is a Canadian innovation used to describe how hot the weather feels to the average person. It combines air temperature and relative humidity into a single value. A Humidex above 40 indicates high discomfort, and above 45 represents dangerous conditions with high risk of heat stroke.
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A-Z Weather Glossary

Air Mass

A large body of air with approximately uniform temperature and humidity throughout. Canadian weather is largely determined by the clash of different air masses — Arctic air from the north, Pacific maritime air from the west, and tropical maritime air from the south.

Arctic Oscillation (AO)

A large-scale atmospheric circulation pattern that influences weather across the Northern Hemisphere. In its negative phase, it allows cold Arctic air to spill southward into Canada and the United States — creating the "polar vortex" events that periodically send extreme cold across the continent.

Blizzard

In Canada, a blizzard is defined by Environment Canada as a weather event with sustained winds or frequent gusts of at least 40 km/h, blowing or falling snow reducing visibility to 400 m or less, and these conditions persisting for at least 4 hours. Wind chill values in blizzards are typically extreme.

Bright Band

A feature visible on weather radar caused by the melting of snowflakes. As snowflakes fall and begin to melt, they temporarily appear larger and produce a stronger radar return, creating a bright horizontal band on radar displays at the altitude where freezing occurs.

Flash Flood

A rapid, sudden flood caused by very heavy rainfall in a short time period. Flash floods typically occur within 6 hours of the causative rainfall event. They are particularly dangerous because they provide little warning time and can produce extremely powerful currents.

Freezing Rain

Rain that falls through a layer of air below 0°C and freezes upon contact with cold surfaces, coating them in ice. Canada is one of the most freezing-rain-prone countries in the world, particularly Ontario and Quebec. Accumulations of just a few millimetres can make roads impassable and bring down power lines.

Humidex

A uniquely Canadian measure that combines air temperature and humidity to reflect the perceived temperature on human skin. A Humidex of 30-39 is uncomfortable; 40-45 is considered dangerous; above 45 is very dangerous. Environment Canada issues heat warnings when Humidex values are expected to reach 40 or higher.

Polar Vortex

A large area of cold, low-pressure air surrounding the Earth's poles. When the polar vortex weakens or becomes displaced, cold Arctic air can spill southward into Canada and the United States, bringing extreme cold events to populated areas far south of the Arctic Circle.

Precipitation

Any form of water (liquid or solid) that falls from clouds and reaches the ground. In Canada, precipitation takes many forms depending on the season and temperature profile: rain, drizzle, snow, sleet, freezing rain, and hail.

Wind Chill

A measure of how cold the air feels on exposed human skin, taking into account both air temperature and wind speed. Environment Canada uses the Wind Chill Index, which was developed in 2001 through a joint Canada-U.S. project. A wind chill of -25 to -44 is dangerous; below -45 is extremely dangerous with frostbite possible in minutes.

Winter Storm Warning

Issued by Environment Canada when two or more of the following conditions are expected: significant snowfall, blowing snow, freezing rain/drizzle, or extreme cold. The warning serves as a signal to avoid unnecessary travel and take winter storm safety precautions.

Blizzard

A severe snowstorm characterized by sustained winds of 40 km/h or more, blowing snow, and visibility reduced to less than 400 meters for at least four hours.

Humidex

An index used by Canadian meteorologists to describe how hot the weather feels, combining temperature and relative humidity.

Jet Stream

A narrow band of strong winds in the upper atmosphere that blows from west to east, directing storm tracks and steering weather systems across Canada.

Squall Line (Ligne de grain)

A narrow band of active thunderstorms, often developing ahead of a cold front, characterized by wind gusts, hail, and torrential rains.

Microburst (Rafale descendante)

An intense, localized column of sinking air (downdraft) within a thunderstorm. When it hits the ground, it spreads out in all directions, creating damaging straight-line winds of up to 150 km/h, which are often mistaken for tornadoes.

Derecho (Derecho)

A widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms. By definition, a derecho must cause wind damage extending over a swath of at least 400 kilometers.