All InfoEnvironmentConnecticut

Environment in Connecticut

Environment data across 288 ZIP codes in Connecticut

Connecticut Snapshot

39

Avg AQI in Connecticut

1,501

EV Stations in Connecticut

50.7°F

Avg Annual Temperature

Last updated May 4, 2026.

How Connecticut compares

Connecticut

39

National Average

43

Connecticut's avg median aqi is 9.2% lower than the national average.

These are the 10 ZIP codes with the best air quality in Connecticut, ranked by lowest median Air Quality Index from EPA AirData. Click any ZIP code for the full local snapshot.

Best Air Quality ZIP Codes in Connecticut

#ZIP CodeCityMedian AQI
106226Willimantic34
206234East Brooklyn34
30623534
406239Danielson34
506241Dayville34
60624234
70624334
80624734
906255Quinebaug34
1006256Willimantic34

FAQ

How many ZIP codes does Mubboo track in Connecticut?

Mubboo tracks 288 ZIP codes in Connecticut via the U.S. Census ZCTA basemap. Use the search box above to look up data for any specific ZIP.

How does Connecticut's average median air quality index compare nationally?

Connecticut's average median air quality index is lower the national average. See the "How Connecticut compares" callout above for the precise side-by-side comparison.

How fresh is this data?

Mubboo refreshes each data source on its native cadence — HUD Fair Market Rents annually (October), Tax Foundation tables annually, and federal datasets per their published schedules. Each page caches for 24 hours via ISR. See our methodology page for details.

Data sources: EPA Air Quality System (AQS), NOAA NCEI 1991-2020 Climate Normals, U.S. DOE Alternative Fuels Data Center. Mubboo refreshes each source on its native cadence (HUD annually, Tax Foundation annually, etc.). See our full methodology →

More Connecticut data:

← All Environment data across America

By Mubboo Editorial Team

Last reviewed May 4, 2026


Data sources

State-level aggregates for Connecticut. Individual ZIP-code values may differ — use the ZIP search above for granular data.

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