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Air Quality Index

Cultural  
  1. A measure of the quantity of harmful particles and chemicals in the air.


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The index is used by weather forecasters to indicate the purity of the air on a given day. The higher the index, the smoggier (see smog) and more polluted the air.

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Singapore's air quality levels too dipped into the "very unhealthy" range with a reading of 209 on the Air Quality Index in Friday afternoon, according to the IQAir website.

From Barron's ● Oct. 9, 2026

Under a heat dome, those pollutants can linger longer, leading to elevated Air Quality Index, or AQI, readings that may pose additional risks for people with asthma and other respiratory conditions.

From Salon ● Jul. 3, 2026

On Wednesday, we had a rare afternoon where the Air Quality Index was below 100.

From Slate ● Feb. 12, 2026

It uses the government's Daily Air Quality Index to determine when alerts are triggered.

From BBC ● Aug. 12, 2025

For those who wish to view the Air Quality Index forecast, or for real-time air quality updates, visit AQMD.gov.

From Los Angeles Times ● Jan. 17, 2024

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