Stay updated with real-time air quality in Colchester, 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)
44
Good
Colchester, Connecticut
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
8.01 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
28.96 μg/m³
0
55
155
255
425
605+
19.63 ppb
0
55
71
86
201
201+
0.18 ppb
0
36
76
186
605
1005+
7.94 ppb
0
54
101
361
1250
2050+
0.20 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Colchester, Connecticut
Colchester, Connecticut
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AQI 52
Moderate
10.17μg/m³
PM2.5
35.72μg/m³
PM10
19.10ppb
O3
0.32ppb
SO2
20.43ppb
NO2
0.51ppm
CO
AQI 49
Good
8.80μg/m³
PM2.5
15.49μg/m³
PM10
29.21ppb
O3
0.36ppb
SO2
18.74ppb
NO2
0.56ppm
CO
AQI 38
Good
7.23μg/m³
PM2.5
29.04μg/m³
PM10
25.18ppb
O3
0.40ppb
SO2
14.13ppb
NO2
0.56ppm
CO
AQI 58
Moderate
12.81μg/m³
PM2.5
21.95μg/m³
PM10
7.76ppb
O3
0.33ppb
SO2
19.34ppb
NO2
0.63ppm
CO
AQI 52
Moderate
10.39μg/m³
PM2.5
36.20μg/m³
PM10
23.72ppb
O3
0.40ppb
SO2
12.26ppb
NO2
0.55ppm
CO
AQI 44
Good
7.61μg/m³
PM2.5
33.50μg/m³
PM10
22.13ppb
O3
0.37ppb
SO2
23.29ppb
NO2
0.57ppm
CO
Air quality measurements for Connecticut, USA meet strict US EPA standards. These measurements are collected from reliable sources, including satellites and ground-based monitoring systems. Advanced algorithms and machine learning techniques are applied to the data, factoring in variables such as traffic and population density, to ensure precision and reliability.
Source: Ambee Data Sources
Air quality data for Colchester, Connecticut is updated on an hourly basis.
The worst air quality in Colchester, Connecticut was recorded at 05:00:00 on 2025-11-03.
The best air quality in Colchester, Connecticut was recorded at 04:00:00 on 2025-11-02.
The real-time air quality index in Colchester, Connecticut is 54, currently categorized as Moderate.
The most common pollutant in Colchester, Connecticut is PM2.5.
If the air quality in Colchester, Connecticut is poor, limit outdoor activities and use a mask to safeguard your health.
The measured PM2.5 levels in Colchester, Connecticut at present are 10.708 μg/m3.
The current PM10 levels in Colchester, Connecticut are 36.382 μg/m3.
The current carbon monoxide (CO) level in Colchester, Connecticut is 0.476 ppm.
The current sulfur dioxide (SO2) levels in Colchester, Connecticut are 0.266 ppb.
The current ozone (O3) levels at Colchester, Connecticut is 20.757 ppm.
The current nitrogen dioxide (NO2) levels at Colchester, Connecticut is 20.384 ppb.
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