How to Read Idaho Air Quality and AQI
The Air Quality Index turns several pollutants into a common scale so you can quickly understand the level of concern.
The AQI scale
AQI categories range from Good through Hazardous. Higher numbers represent greater air-pollution concern and increasing health guidance.
Why the number changes
Smoke plumes move with wind and terrain. A location can improve or deteriorate quickly, especially during Idaho wildfire season.
PM2.5 during smoke events
Fine particulate matter is a major reason wildfire smoke can drive AQI higher. Ozone and other regulated pollutants can also determine the AQI depending on conditions.
Official guidance
Use the Idaho Department of Environmental Quality and public-health guidance when air quality affects health decisions.
AQI is pollutant-specific before it becomes one number
Monitoring systems calculate an index value for individual pollutants and the reported AQI is generally driven by the pollutant producing the highest level of concern. During smoke events that is often fine particulate matter, but ozone can dominate under different conditions. That is why the same AQI value can come from different underlying air-quality situations.
Look at trend and duration
A brief spike and an all-day elevated reading are not the same exposure pattern. If smoke is moving through an area, check whether the AQI is improving or worsening and whether the forecast suggests a wind shift. People with health concerns should use current public-health guidance rather than relying on a general description of the color category.
Authoritative references
Published September 30, 2026 · IdahoLens.com
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