What’s with the colour-coded weather alerts? Here’s what you need to know

TORONTO — A snowstorm has reintroduced southern Ontario to some severe winter weather Thursday, as well as a relatively new warning system from Environment Canada.

The new system, rolled out in November, attaches a colour to every type of weather alert: warnings, advisories and watches.

The yellow, orange and red alerts are intended to help people quickly and clearly understand the effects of weather — not just what it will be, but what it could do to people, property and communities.

On Thursday morning, the Greater Toronto Area and Ottawa woke up to an orange alert, along with big piles of snow.

Here’s a bit more about what each of the colour-coded warnings means:

Yellow

These are the most common alerts.

They’re issued when weather could cause damage, disruption or health impacts, but when the impacts are expected to be moderate, localized and short-term.

Environment Canada introduced the system using windstorms as an example.

During a yellow windstorm, there could be effects such as short-term utility outages and risk of injury from falling branches or other debris.

Orange

Orange alerts are less common than yellow, and they are intended to communicate when severe weather is likely to result in significant damange, disruption or health impacts.

Those impacts can be major, widespread or last a few days.

An orange windstorm, for example, could see widespread utility outages, some roof damage, trees snapping and an increased injury risk.

Red

This is as serious as it gets. A red alert is issued when weather is very dangerous and possibly life-threatening. Impacts have the potential to be extensive, widespread and prolonged.

It’s issued only when the impact is expected to be extreme and the forecast confidence is very high.

During a red windstorm warning, there may be a high likelihood of injury from falling debris, widespread and long-lasting power outages, structural damage to homes and buildings, and significant damage to trees, including parks and orchards.

Some historical references to a “red” alert storm include the 1998 ice storm that devastated transmission towers in Ontario and Quebec, or the 2021 atmospheric river that led to severe flooding in British Columbia.

This report by The Canadian Press was first published Jan. 15, 2026.

Jordan Omstead, The Canadian Press