Weather Alerts and Colour Codes

Environment Canada is the authoritative source for weather information in Canada. They issue weather alerts to let you know about noteworthy weather and how it can impact you.

A weather alert gives you information that helps you to take appropriate action to keep yourself, your loved ones, and your property safe. Our alerts are impact-based, and tell you what the weather will do (for example, potential power outages), in addition to what it will be (for example, a severe thunderstorm).

Weather Alerts

The three types of alerts are Warnings, Advisories, and Watches.  

Each depends on severity of the weather, timing, and how quickly you should act.

Warnings

• act now to protect yourself from severe weather
• urgent messages that severe weather is either happening or will happen
• usually issued 6 to 24 hours in advance, but can be longer
• some severe weather (for example, tornadoes) can occur rapidly, with less than 30 minutes’ notice

Advisories 

• act now to protect yourself from significant weather
• issued for specific weather events that are less severe but still significant
• issued for blowing snow, fog, freezing drizzle, and frost

Watches

• get ready to protect yourself from potential severe weather
• issued when conditions are favorable for the development of severe weather
• may be upgraded to a Warning when certainty increases

Colour Coded Weather Alerts

Environment Canada alerts are colour-coded. The colours tell you what risk the weather is to you. Every type of weather alert—Warnings, Advisories, and Watches—now has a colour when it is issued.