Stay updated with real-time air quality in Greenwich, Connecticut featuring accurate data on AQI, PM2.5, PM10, O3, NO2, SO2, and CO levels. Use our interactive map and detailed forecasts to monitor pollution trends, manage health risks, and plan your daily activities with confidence.
Live AQI (Air Quality Index)
27
Good
Greenwich, Connecticut
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
2.56 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
9.00 μg/m³
0
55
155
255
425
605+
29.14 ppb
0
55
71
86
201
201+
0.28 ppb
0
36
76
186
605
1005+
8.91 ppb
0
54
101
361
1250
2050+
0.18 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Greenwich, Connecticut
Greenwich, Connecticut
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AQI 34
Good
1.84μg/m³
PM2.5
7.98μg/m³
PM10
36.73ppb
O3
0.15ppb
SO2
4.04ppb
NO2
0.11ppm
CO
AQI 30
Good
1.96μg/m³
PM2.5
8.46μg/m³
PM10
31.53ppb
O3
0.30ppb
SO2
4.55ppb
NO2
0.11ppm
CO
AQI 34
Good
1.81μg/m³
PM2.5
6.84μg/m³
PM10
36.72ppb
O3
0.26ppb
SO2
2.09ppb
NO2
0.11ppm
CO
AQI 30
Good
1.95μg/m³
PM2.5
8.42μg/m³
PM10
31.54ppb
O3
0.30ppb
SO2
4.48ppb
NO2
0.11ppm
CO
AQI 30
Good
1.90μg/m³
PM2.5
8.02μg/m³
PM10
31.96ppb
O3
0.16ppb
SO2
3.34ppb
NO2
0.11ppm
CO
AQI 29
Good
1.97μg/m³
PM2.5
8.54μg/m³
PM10
31.39ppb
O3
0.34ppb
SO2
4.82ppb
NO2
0.11ppm
CO
Air quality data and pollutant measurements for Connecticut, USA adhere to strict US EPA standards. The data is collected from multiple reliable sources, including satellites and ground-based monitoring stations. This data is further analyzed and enhanced using machine learning and advanced algorithms that factor in elements such as traffic and population density, ensuring accurate and reliable results.
Source: Ambee Data Sources
The air quality for Greenwich, Connecticut is updated every hour.
The worst air quality in Greenwich, Connecticut in the last 24 hours was observed at 02:00:00 on 2025-11-04.
In the last 24 hrs, the best air quality in Greenwich, Connecticut was observed at 06:00:00 on 2025-11-04.
The current air quality in Greenwich, Connecticut is 33, categorized as Good based on real-time data.
The most common pollutant in Greenwich, Connecticut is O3.
If the air quality in Greenwich, Connecticut is poor, consider staying indoors and wearing a mask to protect yourself.
The current PM2.5 concentration at Greenwich, Connecticut is 1.666 μg/m3.
The current PM10 concentration at Greenwich, Connecticut is 8.502 μg/m3.
The current carbon monoxide (CO) concentration at Greenwich, Connecticut is 0.109 ppm.
The current sulfur dioxide (SO2) concentration at Greenwich, Connecticut is 0.146 ppb.
The current ozone (O3) concentration at Greenwich, Connecticut is 35.776 ppm.
The current nitrogen dioxide (NO2) concentration at Greenwich, Connecticut is 3.09 ppb.
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