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)
30
Good
Greenwich, Connecticut
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
5.43 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
14.59 μg/m³
0
55
155
255
425
605+
24.08 ppb
0
55
71
86
201
201+
0.77 ppb
0
36
76
186
605
1005+
31.95 ppb
0
54
101
361
1250
2050+
0.28 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
High
Greenwich, Connecticut
Greenwich, Connecticut
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AQI 28
Good
5.28μg/m³
PM2.5
13.50μg/m³
PM10
26.83ppb
O3
0.78ppb
SO2
29.59ppb
NO2
0.27ppm
CO
AQI 27
Good
4.09μg/m³
PM2.5
12.67μg/m³
PM10
25.55ppb
O3
0.80ppb
SO2
28.59ppb
NO2
0.27ppm
CO
AQI 33
Good
6.01μg/m³
PM2.5
14.37μg/m³
PM10
28.30ppb
O3
0.74ppb
SO2
27.63ppb
NO2
0.26ppm
CO
AQI 26
Good
3.43μg/m³
PM2.5
11.70μg/m³
PM10
24.93ppb
O3
0.81ppb
SO2
28.09ppb
NO2
0.27ppm
CO
AQI 25
Good
0.27μg/m³
PM2.5
0.83μg/m³
PM10
23.12ppb
O3
0.79ppb
SO2
26.36ppb
NO2
0.27ppm
CO
AQI 26
Good
3.92μg/m³
PM2.5
14.38μg/m³
PM10
25.03ppb
O3
0.82ppb
SO2
28.25ppb
NO2
0.27ppm
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 12:00:00 on 2026-05-14.
In the last 24 hrs, the best air quality in Greenwich, Connecticut was observed at 12:00:00 on 2026-05-14.
The current air quality in Greenwich, Connecticut is 30, categorized as Good based on real-time data.
The most common pollutant in Greenwich, Connecticut is NO2.
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 5.426 μg/m3.
The current PM10 concentration at Greenwich, Connecticut is 14.592 μg/m3.
The current carbon monoxide (CO) concentration at Greenwich, Connecticut is 0.282 ppm.
The current sulfur dioxide (SO2) concentration at Greenwich, Connecticut is 0.768 ppb.
The current ozone (O3) concentration at Greenwich, Connecticut is 24.08 ppm.
The current nitrogen dioxide (NO2) concentration at Greenwich, Connecticut is 31.946 ppb.
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