Heat is the quiet killer.
More people die from heat each year in the US and Canada than from any other weather hazard. Warnings arrive quietly — a bulletin, not a siren — and the danger builds across days, not hours.
Advisory · Warning · HeatRisk.
The NWS issues Heat Advisories, Excessive Heat Watches, and Excessive Heat Warnings based on heat index and duration. The newer HeatRisk index (green→magenta) accounts for local acclimatization and vulnerable populations.
Heat warnings and Humidex.
ECCC issues heat warnings on province-specific thresholds combining temperature and humidity (often via Humidex). Some provinces run tiered systems — 'heat warning' and 'extended heat warning' — and municipal health units activate cooling centres independently.
Active alerts right now.
Point-based lookup covers US zones only. Canadian users: browse alerts by hazard below.
One or more upstream feeds are temporarily unavailable. Check the source links below.
If an alert covers you.
- →Drink water before you feel thirsty. By thirst you're already behind.
- →Never leave children or pets in a parked car — interior temperatures can rise 20°F/11°C in 10 minutes.
- →Check on elderly neighbours, people living alone, and anyone without AC at least twice a day.
- →Move to a cooling centre, library, or mall if your home stays above 26°C/80°F overnight.
- →Watch for heat stroke: hot dry skin, confusion, no sweating. This is a medical emergency — call 911.