Think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 or below represents good air quality, while an AQI value over 300 represents hazardous air quality.

201-300: Very Unhealthy: Health warnings of emergency conditions. The entire population is more likely to be affected. Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion. 300+ Hazardous

Sep 18, 2024 · The Air Quality Index, or AQI, is the system used to warn the public when air pollution is dangerous. The AQI tracks ozone (smog) and particle pollution (tiny particles from smoke, power plants and factories, vehicle exhaust, and other sources), as well as four other widespread air pollutants.

AQI value of 50 represents good air quality with little or no potential to affect public health, while an AQI value over 300 represents air quality so hazardous that everyone may experience serious effects. An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set

2 days ago · Monitor your location's AQI in real-time. Get the latest air quality index and pollution levels, updated frequently for accurate, actionable information.

This color-coded table shows generically how AQI values correlate with levels of health concern. For a copy of this AQI table, download the booklet, "Air Quality Index - A Guide to Air Quality and Your Health," that explains the AQI and the health effects of major air pollutants, at https://www.epa.gov/airnow/aqi_brochure_08-09.pdf .

Jun 8, 2023 · Here’s how to understand the Environmental Protection Agency’s Air quality index (AQI), which measures, on a 300-point scale (along with six categories and advisories), the quality of...

Mar 20, 2025 · Since levels rarely exceed a value of 200 in the United States, in most cases only the range from 0 to 300 is shown. The higher the AQI value, the greater the level of pollution and the greater the health concern. An AQI value of 100 generally corresponds to the level of the National Ambient Air Quality Standard for the pollutant.

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What is the AQI? The EPA and your State environmental agency measure pollution in the air. Then they use the Air Quality Index, or AQI, to tell the people about the air. An index can be a quick way to tell people how good or bad something is. The AQI uses colors, and numbers, and words to tell you about the air. These are the AQI colors.