Region 1: EPA New England

2021 Ozone Exceedances

(Through September 30, 2021)

Below are the exceedances of the 0.070 parts per million (ppm) eight-hour average ozone standard, and the dates they occurred for each ozone monitor in New England. These data are preliminary, not quality assured and are subject to change.

Connecticut
Monitor Location Date Concentration (ppm)  
Madison August 27, 2021 0.084 Peak Ozone AQI
Danbury August 26, 2021 0.074 Peak Ozone AQI
Greenwich August 26, 2021 0.094
Groton August 26, 2021 0.076
Madison August 26, 2021 0.085
Middletown August 26, 2021 0.079
Stratford August 26, 2021 0.087
Westport August 26, 2021 0.099
Greenwich August 13, 2021 0.076 Peak Ozone AQI
Groton August 13, 2021 0.076
Madison August 13, 2021 0.073
Stratford August 13, 2021 0.080
Westport August 13, 2021 0.082
Madison August 12, 2021 0.078 Peak Ozone AQI
Middletown August 12, 2021 0.079
Stratford August 12, 2021 0.073
Westport August 12, 2021 0.073
Westport August 11, 2021 0.071 Peak Ozone AQI
Groton August 7, 2021 0.075 Peak Ozone AQI
Madison August 7, 2021 0.083
New Haven August 7, 2021 0.078
Stratford August 7, 2021 0.074
Danbury August 6, 2021 0.072 Peak Ozone AQI
Greenwich August 6, 2021 0.078
Madison August 6, 2021 0.077
Middletown August 6, 2021 0.071
Stratford August 6, 2021 0.080
Westport August 6, 2021 0.080
Greenwich July 27, 2021 0.072 Peak Ozone AQI
Greenwich July 16, 2021 0.076 Peak Ozone AQI
Middletown July 16, 2021 0.076
Stratford July 16, 2021 0.087
Westport July 16, 2021 0.087
Greenwich July 7, 2021 0.077 Peak Ozone AQI
Madison July 7, 2021 0.089
New Haven July 7, 2021 0.081
Stratford July 7, 2021 0.091
Westport July 7, 2021 0.089
Middletown July 6, 2021 0.077 Peak Ozone AQI
Stratford July 6, 2021 0.071
Westport July 6, 2021 0.078
Greenwich June 30, 2021 0.078 Peak Ozone AQI
Madison June 30, 2021 0.079
Middletown June 30, 2021 0.078
New Haven June 30, 2021 0.071
Stratford June 30, 2021 0.080
Westport June 30, 2021 0.085
Greenwich June 29, 2021 0.077 Peak Ozone AQI
Middletown June 29, 2021 0.074
Stratford June 29, 2021 0.072
Westport June 29, 2021 0.080
Middletown June 28, 2021 0.072 Peak Ozone AQI
Groton June 19, 2021 0.072 Peak Ozone AQI
Madison June 19, 2021 0.081
Stratford June 19, 2021 0.073
Middletown June 18, 2021 0.076 Peak Ozone AQI
Danbury June 7, 2021 0.071 Peak Ozone AQI
East Hartford June 7, 2021 0.074
Greenwich June 7, 2021 0.072
Greenwich June 6, 2021 0.082 Peak Ozone AQI
Groton June 6, 2021 0.074
Madison June 6, 2021 0.077
Middletown June 6, 2021 0.071
Stratford June 6, 2021 0.078
Westport June 6, 2021 0.086
Abington June 5, 2021 0.082 Peak Ozone AQI
Greenwich June 5, 2021 0.071
Groton June 5, 2021 0.079
Madison June 5, 2021 0.083
Middletown June 5, 2021 0.086
New Haven June 5, 2021 0.076
Stratford June 5, 2021 0.086
Westport June 5, 2021 0.080
Danbury May 26, 2021 0.075 Peak Ozone AQI
Stafford May 26, 2021 0.071
Cornwall May 21, 2021 0.076 Peak Ozone AQI

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Maine
Monitor Location Date Concentration (ppm)  
Cape Elizabeth August 26, 2021 0.073 Peak Ozone AQI
Kennebunkport August 26, 2021 0.079
Bar Harbor—Cadillac Mtn. August 7, 2021 0.072 Peak Ozone AQI
Acadia NP—McFarland June 7, 2021 0.072 Peak Ozone AQI
Bar Harbor—Cadillac Mtn. June 7, 2021 0.076
Cape Elizabeth June 7, 2021 0.079
Kennebunkport June 7, 2021 0.075
Port Clyde June 7, 2021 0.072
Acadia NP—McFarland June 6, 2021 0.075 Peak Ozone AQI
Bar Harbor—Cadillac Mtn. June 6, 2021 0.080
Cape Elizabeth June 6, 2021 0.075
Kennebunkport June 6, 2021 0.077
Port Clyde June 6, 2021 0.076
Shapleigh Ball Park June 6, 2021 0.071

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Massachusetts
Monitor Location Date Concentration (ppm)  
Fairhaven August 26, 2021 0.084 Peak Ozone AQI
Fall River August 26, 2021 0.078
Truro August 26, 2021 0.078
Fairhaven June 6, 2021 0.071 Peak Ozone AQI
Fall River June 6, 2021 0.071
Truro June 6, 2021 0.073
Weymouth June 6, 2021 0.073
Boston—Roxbury June 5, 2021 0.074 Peak Ozone AQI
Brockton June 5, 2021 0.071
Truro June 5, 2021 0.071
Uxbridge June 5, 2021 0.072
Weymouth June 5, 2021 0.077
Chicopee May 26, 2021 0.072 Peak Ozone AQI

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New Hampshire
Monitor Location Date Concentration (ppm)  
Odiorne State Park August 26, 2021 0.077 Peak Ozone AQI
Summit August 16, 2021 0.080 Peak Ozone AQI
Concord June 6, 2021 0.071 Peak Ozone AQI
Odiorne State Park June 6, 2021 0.075

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Rhode Island
Monitor Location Date Concentration (ppm)  
East Providence August 26, 2021 0.071 Peak Ozone AQI
Narragansett August 26, 2021 0.083
East Matunuck August 13, 2021 0.071 Peak Ozone AQI
East Providence June 6, 2021 0.071 Peak Ozone AQI
Narragansett June 6, 2021 0.073
West Greenwich June 6, 2021 0.074
East Providence June 5, 2021 0.081 Peak Ozone AQI
West Greenwich June 5, 2021 0.082
East Matunuck May 18, 2021 0.073 Peak Ozone AQI

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Vermont
Monitor Location Date Concentration (ppm)  
None      

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