Environment Canada weather alerts: what yellow, orange and red mean
On 26 November 2025 ECCC added a colour to every watch, advisory and warning and replaced its fixed criteria with Weather Impact Guides. How the colour is chosen and how to read it.
Since 26 November 2025, every Environment and Climate Change Canada (ECCC) watch, advisory and warning carries a colour. Yellow means hazardous weather may cause damage, disruption or health impacts that are moderate, localized or short-term; it is the most common. Orange means severe weather is likely to cause significant damage, disruption or health impacts that are major, widespread or may last a few days; it is uncommon. Red means very dangerous, possibly life-threatening weather that will cause extreme damage and disruption; it is rare. The colour comes from the expected impact and how confident forecasters are, not from a fixed amount of rain, snow or wind.
What changed on 26 November 2025?
- Colours on every alert. Warnings, advisories and watches are issued as yellow, orange or red, and the colour is part of the name: "Yellow Warning - Wind", "Orange watch - tornado".
- Impact Guides instead of criteria. ECCC's page of criteria for public weather alerts now says its Weather Impact Guides "replace the previous criteria".
- Statements are not alerts. Special weather statements have no colour; ECCC issues them "for information only".
- Marine warnings are left out. They are a separate program and do not use colour-coded alerts.
The colours also changed meaning. ECCC's older guide to its alert maps (2022) used red for warnings, yellow for watches and dark grey for special weather statements. Now a yellow area can be a warning and a watch can be orange, so yellow no longer means "watch". The difference between the alert types themselves is explained in special weather statement vs watch vs warning.
What do yellow, orange and red alerts mean?
ECCC illustrates each colour with a wind warning. The descriptions are ECCC's own:
| Colour | What ECCC says | Impacts | How often | In a wind warning you may see |
|---|---|---|---|---|
| Yellow | Hazardous weather may cause damage, disruption or health impacts | Moderate, localized and/or short-term | Most common | Some short-term utility outages, larger tree branches broken |
| Orange | Severe weather is likely to cause significant damage, disruption or health impacts | Major, widespread and/or may last a few days | Uncommon | Widespread utility outages, some roof damage, small to medium trees snapped |
| Red | Very dangerous and possibly life-threatening weather will cause extreme damage and disruption | Extensive, widespread and prolonged | Rare | Long, widespread utility outages, structural damage to homes and buildings |
Yellow is not a low-risk colour to ignore. ECCC's guides say all weather "can be life-threatening at any impact level", and low-impact weather does not get an alert at all.
How does Environment Canada choose the colour?
Forecasters place each event on an Alert Colour Matrix: the expected impact (moderate, high or extreme) against their confidence that it will happen (low, moderate, high or very high). Where the two meet is the colour:
| Forecast confidence | Moderate impact | High impact | Extreme impact |
|---|---|---|---|
| Low | No alert | Yellow | Yellow |
| Moderate | No alert | Yellow | Orange |
| High | Yellow | Orange | Orange |
| Very high | Yellow | Orange | Red |
Three things follow from the matrix. Red needs both extreme impact and very high confidence, which is why it is rare. An event that could be extreme but is still uncertain is yellow, and it only turns orange once forecasters are at least moderately confident. And moderate weather gets no alert until forecasters are highly confident it will happen. ECCC sets its confidence from current observations, weather prediction models and forecaster expertise.
What replaced the old warning criteria?
Weather Impact Guides. Before the change, ECCC published fixed thresholds for each region. On its criteria page in 2024, for example, a snowfall warning needed 15 cm or more within 12 hours in Ontario, most of Quebec and Atlantic Canada, but 10 cm in 12 hours on the Prairies; a severe thunderstorm warning needed wind gusts of 90 km/h or more, hail 2 cm or larger, or heavy rain. Those tables are gone.
The guides cover 14 hazards: coastal flooding, cold, frost, heat, hurricanes and tropical storms, ice, rain, snow, snow squalls, thunderstorms, tornadoes, visibility (including blizzards, blowing snow, dust and fog), wind and winter storms. For each, they describe what moderate, high and extreme impact looks like. For snow:
- Moderate: travel disruptions from route closures and collisions, injuries from exertion and falls.
- High: dangerous travel, long delays, property or tree damage, roofs at increased risk of collapsing under the snow.
- Extreme: travel extremely unsafe or impossible, damage to some critical infrastructure, snowed-in residents.
The same snowfall can land at different levels. ECCC says impact depends on location, existing conditions such as snow already on the ground, timing, and how vulnerable the area or people are. The guides list primary impacts only, not secondary ones such as school or business closures, so the colour does not tell you whether your school will close.
What does a yellow vs an orange warning look like?
Two severe thunderstorm warnings ECCC issued in central Alberta on 4 July 2026, half an hour apart, show the difference:
| Time (MDT) | Alert | Area | What ECCC expected |
|---|---|---|---|
| 4:17 p.m. | Yellow warning - severe thunderstorm | Clearwater County, near Rocky Mountain House | Strong wind gusts, loonie to ping pong ball size hail and heavy rain |
| 4:46 p.m. | Orange warning - severe thunderstorm | Lacombe County, near Lacombe, Blackfalds and Bentley | Damaging wind gusts, golf ball to tennis ball size hail and heavy rain; "Large hail will likely cause significant damage and injury." |
Same alert type, same hazard, same afternoon. The second storm was expected to bring bigger hail and significant damage, and it went out as orange. Watches work the same way: ECCC issued an orange tornado watch for Woodlands County, Alberta, on 15 July 2026.
How do you read an alert on the map and in the app?
- Read the whole name. Colour, type, hazard: "Yellow Warning - Wind". The colour is the expected impact. The type tells you what to do: get ready for a watch, act now for an advisory or warning.
- On ECCC's Weather Information map, solid colours with solid outlines are warnings or advisories, transparent colours with dotted outlines are watches, and grey areas are weather statements. Select a coloured area to open the alert.
- Do not read yellow as "watch". On the old maps it was; now a solid yellow area is a warning or advisory.
- Read the full text. ECCC says to read the full alert whatever the colour, because every alert includes actions you can take to keep safe.
Is it the same as the UK's yellow, amber and red warnings?
The idea is the same. The Met Office colours its warnings yellow, amber or red from a combination of the impact the weather may have and the likelihood of that impact, shown in a matrix, as explained in Met Office weather warnings explained. The Canadian middle colour is orange rather than amber.
Where does the forecast confidence come from?
Confidence is half of every colour, and ECCC builds it partly from weather prediction models. You can see part of that picture yourself. Our Canada forecast pages put Environment Canada's GEM model, the European ECMWF and the American GFS side by side, with a forecast confidence line and a flag on every day where the models split, and our accuracy scoreboard shows which model has been closest over the last 30 days. Treat that as context: the colour on an ECCC alert is the official call.
Read the colour for how bad it could get and the type for what to do. A yellow warning is still a warning, an orange watch is a serious reason to get ready, and a grey statement is information. Whatever the colour, open the alert and read the actions.