Worcester County, Massachusetts

AQI 42 · Good

YearMonth

42

Median AQI

62

90th Percentile

100

Max AQI

244

Days with Data

Ranked #12 of 13 counties in Massachusetts (by median AQI, lower is better)

Monthly Median AQI — 2025

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AQI Category Breakdown

Adjacent Counties

Tolland County, Connecticut Windham County, Connecticut Franklin County Hampden County Hampshire County Middlesex County Norfolk County Cheshire County, New Hampshire Hillsborough County, New Hampshire Providence County, Rhode Island

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