Planning guidance, not a guarantee. Conditions can vary within a forecast area. Follow current official instructions and use local judgment for your route, equipment, health, and surroundings.
Use the AQI category and number together
The US AQI translates pollutant measurements into health guidance bands. The leading pollutant helps explain what is driving the number, and local monitors or modeled grids may represent a wider area rather than one address.
Activity and duration matter
Longer or more vigorous outdoor activity increases exposure. People who know they are unusually sensitive can ask Nature Says When to apply more cautious rules without creating a medical profile.
Smoke and AQI answer different questions
Satellite-observed smoke can be aloft without producing the same ground-level particle concentration everywhere. Use ground-level AQI for the breathing-level signal and smoke products for plume context.
Primary sources
These are the authoritative references behind this guide’s planning context.
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