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)
29
Good
Colchester, Connecticut
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
2.11 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
14.75 μg/m³
0
55
155
255
425
605+
30.61 ppb
0
55
71
86
201
201+
0.34 ppb
0
36
76
186
605
1005+
9.91 ppb
0
54
101
361
1250
2050+
0.22 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 29
Good
1.29μg/m³
PM2.5
4.64μg/m³
PM10
31.08ppb
O3
0.23ppb
SO2
6.24ppb
NO2
0.23ppm
CO
AQI 29
Good
1.03μg/m³
PM2.5
2.77μg/m³
PM10
30.59ppb
O3
0.32ppb
SO2
2.69ppb
NO2
0.24ppm
CO
AQI 27
Good
0.86μg/m³
PM2.5
3.91μg/m³
PM10
28.81ppb
O3
0.30ppb
SO2
6.00ppb
NO2
0.24ppm
CO
AQI 29
Good
1.25μg/m³
PM2.5
3.17μg/m³
PM10
30.89ppb
O3
0.21ppb
SO2
5.54ppb
NO2
0.21ppm
CO
AQI 28
Good
1.07μg/m³
PM2.5
3.84μg/m³
PM10
30.08ppb
O3
0.32ppb
SO2
3.81ppb
NO2
0.24ppm
CO
AQI 28
Good
0.89μg/m³
PM2.5
2.61μg/m³
PM10
30.06ppb
O3
0.27ppb
SO2
6.24ppb
NO2
0.23ppm
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 02:00:00 on 2025-11-06.
The best air quality in Colchester, Connecticut was recorded at 10:00:00 on 2025-11-06.
The real-time air quality index in Colchester, Connecticut is 28, currently categorized as Good.
The most common pollutant in Colchester, Connecticut is O3.
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 1.044 μg/m3.
The current PM10 levels in Colchester, Connecticut are 2.923 μg/m3.
The current carbon monoxide (CO) level in Colchester, Connecticut is 0.201 ppm.
The current sulfur dioxide (SO2) levels in Colchester, Connecticut are 0.303 ppb.
The current ozone (O3) levels at Colchester, Connecticut is 30.457 ppm.
The current nitrogen dioxide (NO2) levels at Colchester, Connecticut is 9.329 ppb.
All Rights Reserved © Ambee Inc. 2025