PurpleAir
Community-Powered Air Quality Monitoring
United States (global sensor network)
Highlight
A dense network of low-cost citizen sensors maps fine-particle pollution (PM2.5) in real time, street by street.
Extended description
PurpleAir is a real-time, community-powered air-quality network built from thousands of low-cost sensors installed by residents, schools, businesses and agencies to measure fine particulate matter (PM2.5). Readings appear on an interactive global map, revealing pollution differences between neighbourhoods and even individual streets and updating every few minutes. The dense citizen network complements official monitoring and helps people respond to events such as wildfire smoke.