Mercer County, New Jersey
AQI 43 · Good43
Median AQI
66
90th Percentile
122
Max AQI
235
Days with Data
Ranked #13 of 15 counties in New Jersey (by median AQI, lower is better)
Monthly Median AQI — 2025
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43
Median AQI
66
90th Percentile
122
Max AQI
235
Days with Data
Ranked #13 of 15 counties in New Jersey (by median AQI, lower is better)
Click a bar to view that month's details