Purple Air: Realtime Air Quality Conditions
The map below is generated by PurpleAir. This grassroots organization relies on volunteers to allow air sensors to be placed on their businesses or homes. PurpleAir uses the same scale that the Environmental Protection Agency uses – the Air Quality Index scale – to compare and measure pollutants in the air.
The scale uses green for good, yellow for moderate, orange for unhealthy for sensitive groups, red for unhealthy, purple for very unhealthy and maroon for hazardous. The Air Quality Index above is also useful, but only monitors several County-wide sensors. Click here to learn more about AQI.
Understanding Alert Levels

Understanding Air Quality
What impacts our Air Quality
We use a measurement system called AQI (air quality index) developed by the Environmental Protection Agency (EPA) to assign a numerical value to the air quality. This system takes four major air pollutants into account, ground-level ozone, particle pollution, carbon monoxide, and sulfur dioxide. The higher the AQI, the greater the level of air pollution.