PurpleAir
Free trialLiveLast verified 24 Sept 2026
Live and historical PM2.5, temperature and humidity from community sensors, by sensor or bounding box.
Example request
curl -s 'https://api.purpleair.com/v1/sensors/131075' -H "X-API-Key: $API_KEY"
Free tier, in plain English
New accounts get a million points to spend. After that you buy points, starting at 100,000 per dollar. Sensor owners can read their own sensors for free.
Alternatives in Air Quality
AirNowHourly AQI observations and daily air quality forecasts for the US, Canada and Mexico by zip or coordinate.FreeAQICN (World Air Quality Index)Real-time air quality index, pollutant levels, and forecasts from 11,000+ global monitoring stations.FreeEPAUS EPA Air Quality System: ambient air monitor readings by site, county, or state.FreeIQAir AirVisualCurrent US and China AQI plus weather for the nearest city by GPS, IP or name, from hourly station readingsFreemiumLuchtmeetnetReal-time and forecast air quality measurements from Dutch government monitoring stations.Free