Middlesex County, Connecticut
AQI 42 · Good42
Median AQI
77
90th Percentile
151
Max AQI
122
Days with Data
Ranked #4 of 8 counties in Connecticut (by median AQI, lower is better)
Monthly Median AQI — 2025
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42
Median AQI
77
90th Percentile
151
Max AQI
122
Days with Data
Ranked #4 of 8 counties in Connecticut (by median AQI, lower is better)
Click a bar to view that month's details