The Air Quality Index (AQI) is a numerical scale used to communicate how polluted the air is and what health effects people might experience. In Canada, the Air Quality Health Index (AQHI) rates air quality from 1 (low risk) to 10+ (very high risk), considering pollutants like ground-level ozone, particulate matter, and nitrogen dioxide. When the AQHI is high, vulnerable populations including children, seniors, and those with respiratory conditions should limit outdoor activities. Wildfire smoke has increasingly affected Canadian air quality, with some cities experiencing hazardous conditions during fire season. Environment Canada provides real-time AQHI readings for communities across the country.