Stay updated with real-time air quality in Leicester, Massachusetts 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)
35
Good
Leicester, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
4.25 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
13.50 μg/m³
0
55
155
255
425
605+
38.33 ppb
0
55
71
86
201
201+
0.30 ppb
0
36
76
186
605
1005+
11.26 ppb
0
54
101
361
1250
2050+
0.18 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Moderate
Leicester, Massachusetts
Leicester, Massachusetts
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AQI 36
Good
4.11μg/m³
PM2.5
12.56μg/m³
PM10
38.73ppb
O3
0.28ppb
SO2
9.24ppb
NO2
0.23ppm
CO
AQI 36
Good
4.35μg/m³
PM2.5
11.30μg/m³
PM10
38.79ppb
O3
0.29ppb
SO2
14.70ppb
NO2
0.27ppm
CO
AQI 36
Good
4.69μg/m³
PM2.5
11.01μg/m³
PM10
38.62ppb
O3
0.30ppb
SO2
18.90ppb
NO2
0.30ppm
CO
AQI 36
Good
4.24μg/m³
PM2.5
11.26μg/m³
PM10
38.91ppb
O3
0.29ppb
SO2
13.42ppb
NO2
0.26ppm
CO
AQI 36
Good
4.08μg/m³
PM2.5
12.57μg/m³
PM10
39.17ppb
O3
0.27ppb
SO2
6.45ppb
NO2
0.23ppm
CO
AQI 36
Good
4.44μg/m³
PM2.5
11.04μg/m³
PM10
38.73ppb
O3
0.30ppb
SO2
16.25ppb
NO2
0.28ppm
CO
Air quality and pollutant data for Massachusetts, USA are sourced from ground-based monitors and satellites, adhering to US EPA standards. Machine learning and advanced algorithms enhance the data by incorporating local variables like traffic and population density, ensuring high accuracy and dependability.
Source: Ambee Data Sources
The air quality information for Leicester, Massachusetts is updated every hour for accuracy.
In the past 24 hours, the air quality in Leicester, Massachusetts was at its worst at 02:00:00 on 2026-05-14.
In the last 24 hours, the best air quality in Leicester, Massachusetts was observed at 05:00:00 on 2026-05-13.
As of now, the AQI in Leicester, Massachusetts is 35, indicating Good conditions.
Leicester, Massachusetts air has the highest levels of O3.
Poor air quality in Leicester, Massachusetts means it's advisable to stay indoors and wear a mask for your protection.
PM2.5 levels in Leicester, Massachusetts are currently 4.245 μg/m3.
The PM10 concentration in Leicester, Massachusetts is 13.503 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Leicester, Massachusetts is 0.18 ppm.
Currently, Leicester, Massachusetts has a sulfur dioxide (SO2) concentration of 0.297 ppb.
The current ozone (O3) level in Leicester, Massachusetts at the moment is 38.325 ppm.
Nitrogen dioxide (NO2) level in Leicester, Massachusetts at the moment is 11.255 ppb.
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