Sensor Readings & Environmental Telemetry
Air Quality Index (AQI) & Canadian AQHI
How composite air quality scores translate complex pollutant chemistry into actionable health advice.
The Air Quality Index (AQI) is an international standardized scale from 0 to 500 that converts ambient concentrations of individual air pollutants (PM2.5, PM10, ozone O₃, nitrogen dioxide NO₂, carbon monoxide CO, and sulfur dioxide SO₂) into a single composite risk metric.
In British Columbia and across Canada, Environment and Climate Change Canada (ECCC) also publishes the Air Quality Health Index (AQHI) on a 1 to 10+ scale based on excess mortality relative risk from 3-hour rolling averages of PM2.5, NO₂, and O₃.
Piecewise Linear Breakpoints
The AQI calculation employs piecewise linear interpolation across pollutant concentration breakpoints: I = ((I_high - I_low)/(C_high - C_low)) * (C - C_low) + I_low. The final reported AQI is dictated by the highest sub-index of any single monitored pollutant.
Hyperlocal Sensor Triangulation
Fire Aware sites three environmental nodes in an equilateral ring around your community. By calculating an Inverse Distance Weighted (IDW) interpolation with wind vector bias, Fire Aware detects smoke plumes approaching your neighborhood hours before standard regional stations.