Air Quality Index
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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.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The Air Quality Index peaked at 208, levels more commonly associated with South Asian cities.
From Barron's ● Jul. 2, 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
“Windblown ash particles may be too large to be detected by air quality instrumentation and will not influence Air Quality Index levels,” the advisory stated.
From Los Angeles Times ● Jan. 14, 2025
The Environmental Protection Agency's Air Quality Index, which considers scores above 150 unhealthy, and those above 300 hazardous, spiked to 659 at a monitoring station on the western shore of the Salton Sea.
From Salon ● Jul. 7, 2023
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
