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Planning Outdoor Activities with the Air Quality Index (AQI)

June 17, 2026 · The Clime Team
Planning Outdoor Activities with the Air Quality Index (AQI)

The Air Quality Index (AQI) is a standardized system that measures air pollution levels, providing essential information to help you plan outdoor activities safely. Understanding AQI levels enables you to make informed decisions, protecting your health and that of others.

What Is the AQI?

The AQI is a color-coded scale ranging from 0 to 500, indicating the concentration of pollutants in the air. Higher AQI values correspond to higher pollution levels and greater health risks. The index considers pollutants such as ground-level ozone, particulate matter (PM₂.₅ and PM₁₀), carbon monoxide, sulfur dioxide, and nitrogen dioxide. (epa.gov)

AQI Categories and Recommendations

The AQI is divided into six categories, each with specific health implications and recommended actions:

  • 0-50 (Good): Air quality is satisfactory, and air pollution poses little or no risk. It's safe for everyone to engage in outdoor activities without restrictions.

  • 51-100 (Moderate): Air quality is acceptable; however, some pollutants may be a concern for a small number of individuals sensitive to air pollution. Sensitive individuals should consider limiting prolonged outdoor exertion.

  • 101-150 (Unhealthy for Sensitive Groups): Members of sensitive groups (e.g., children, older adults, individuals with respiratory conditions) may experience health effects. It's advisable for sensitive individuals to reduce outdoor activities, while others can continue with caution.

  • 151-200 (Unhealthy): Everyone may begin to experience health effects; sensitive groups could experience more serious effects. It's recommended to limit outdoor activities, especially strenuous ones.

  • 201-300 (Very Unhealthy): Health alert: everyone may experience more serious health effects. Avoid outdoor activities, and consider staying indoors.

  • 301-500 (Hazardous): Health warning of emergency conditions. The entire population is more likely to be affected. Stay indoors and avoid all outdoor activities. (dhs.wisconsin.gov)

Using AQI to Plan Outdoor Activities

Monitoring the AQI before planning outdoor activities is crucial for health and safety. Here's how to use AQI levels to guide your decisions:

  • AQI 0-50 (Good): Ideal conditions for all outdoor activities. Engage in your planned activities without restrictions.

  • AQI 51-100 (Moderate): Generally safe for outdoor activities. Sensitive individuals should monitor for symptoms like coughing or shortness of breath and consider reducing the intensity or duration of their activities.

  • AQI 101-150 (Unhealthy for Sensitive Groups): Sensitive individuals should limit outdoor activities, especially strenuous ones. Others can continue with reduced intensity and duration.

  • AQI 151-200 (Unhealthy): Limit outdoor activities for everyone, particularly strenuous ones. Sensitive individuals should avoid outdoor exertion.

  • AQI 201-300 (Very Unhealthy): Avoid outdoor activities for everyone. Sensitive individuals should stay indoors.

  • AQI 301-500 (Hazardous): Stay indoors and avoid all outdoor activities. Ensure indoor air quality is maintained. (dhs.wisconsin.gov)

Additional Tips for Planning Outdoor Activities

  • Check AQI Forecasts: Before planning outdoor activities, check the AQI forecast for your area. This information is available on the AirNow website and app. (epa.gov)

  • Time Your Activities: Air quality can vary throughout the day. In many areas, early morning hours often have better air quality before traffic increases and ozone levels rise. (aqitocigarettescalculator.org)

  • Modify Activities as Needed: If the AQI is in the moderate to unhealthy range, consider reducing the intensity or duration of your outdoor activities. Opt for less strenuous exercises or move your workout indoors. (epa.gov)

  • Stay Informed: Be aware of local air quality conditions, especially during events like wildfires or high-traffic periods, which can significantly impact air quality.

By understanding and utilizing the AQI, you can make informed decisions to protect your health while enjoying outdoor activities.

Highlights:

  • Using The Air Quality Index (AQI) to Plan Daily Activities | US EPA, Published on Monday, September 29
  • Climate and Health: Outdoor Activity Recommendations for Unhealthy Air Quality Index Levels | Wisconsin Department of Health Services, Published on Tuesday, October 0710

Frequently Asked Questions