AQI and measurements

Open AIQ presents the US EPA Air Quality Index as a whole number and labels it with these bands:

AQI	Category
0–50	Good
51–100	Moderate
101–150	Unhealthy for Sensitive Groups
151–200	Unhealthy
201–300	Very Unhealthy
301+	Hazardous

Color is accompanied by a category label so meaning does not depend on color alone. Particulate concentrations (PM1.0, PM2.5, PM10) are expressed in micrograms per cubic metre (µg/m³). Temperature is Celsius, humidity is percent relative humidity, and heat index is Celsius.

Firmware computes AQI from particulate measurements. For upload windows it averages concentrations first, then recomputes AQI rather than averaging AQI numbers. The backend current view averages stored readings from the last hour. Historical views bucket records according to the requested timeline.

Consumer sensors, placement, airflow, humidity, calibration, and local conditions all affect results. Do not treat Open AIQ as a certified regulatory monitor or use it as the sole basis for medical or emergency decisions.