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
7.64 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
28.14 μg/m³
0
55
155
255
425
605+
33.96 ppb
0
55
71
86
201
201+
0.27 ppb
0
36
76
186
605
1005+
4.59 ppb
0
54
101
361
1250
2050+
0.17 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Colchester, Connecticut
Colchester, Connecticut
Scroll To Air Quality MapLoading...
AQI 49
Good
9.13μg/m³
PM2.5
41.29μg/m³
PM10
32.20ppb
O3
0.27ppb
SO2
4.26ppb
NO2
0.16ppm
CO
AQI 49
Good
9.34μg/m³
PM2.5
18.67μg/m³
PM10
36.61ppb
O3
0.26ppb
SO2
6.44ppb
NO2
0.16ppm
CO
AQI 44
Good
7.59μg/m³
PM2.5
22.27μg/m³
PM10
32.84ppb
O3
0.23ppb
SO2
4.12ppb
NO2
0.16ppm
CO
AQI 54
Moderate
11.19μg/m³
PM2.5
27.39μg/m³
PM10
33.47ppb
O3
0.27ppb
SO2
3.95ppb
NO2
0.13ppm
CO
AQI 44
Good
7.70μg/m³
PM2.5
20.88μg/m³
PM10
32.39ppb
O3
0.22ppb
SO2
3.91ppb
NO2
0.16ppm
CO
AQI 44
Good
7.81μg/m³
PM2.5
35.72μg/m³
PM10
32.09ppb
O3
0.24ppb
SO2
3.22ppb
NO2
0.15ppm
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 04:00:00 on 2026-06-29.
The best air quality in Colchester, Connecticut was recorded at 05:00:00 on 2026-06-29.
The real-time air quality index in Colchester, Connecticut is 44, currently categorized as Good.
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 7.636 μg/m3.
The current PM10 levels in Colchester, Connecticut are 28.145 μg/m3.
The current carbon monoxide (CO) level in Colchester, Connecticut is 0.174 ppm.
The current sulfur dioxide (SO2) levels in Colchester, Connecticut are 0.267 ppb.
The current ozone (O3) levels at Colchester, Connecticut is 33.962 ppm.
The current nitrogen dioxide (NO2) levels at Colchester, Connecticut is 4.593 ppb.
All Rights Reserved © Ambee Inc. 2025