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)
37
Good
Leicester, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
4.19 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
17.43 μg/m³
0
55
155
255
425
605+
39.97 ppb
0
55
71
86
201
201+
0.30 ppb
0
36
76
186
605
1005+
1.36 ppb
0
54
101
361
1250
2050+
0.14 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Leicester, Massachusetts
Leicester, Massachusetts
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AQI 25
Good
3.94μg/m³
PM2.5
18.83μg/m³
PM10
26.64ppb
O3
0.38ppb
SO2
2.52ppb
NO2
0.15ppm
CO
AQI 33
Good
3.82μg/m³
PM2.5
12.85μg/m³
PM10
36.19ppb
O3
0.22ppb
SO2
1.31ppb
NO2
0.13ppm
CO
AQI 31
Good
3.41μg/m³
PM2.5
8.12μg/m³
PM10
33.84ppb
O3
0.10ppb
SO2
1.01ppb
NO2
0.10ppm
CO
AQI 34
Good
3.93μg/m³
PM2.5
14.38μg/m³
PM10
37.28ppb
O3
0.26ppb
SO2
1.29ppb
NO2
0.13ppm
CO
AQI 23
Good
4.35μg/m³
PM2.5
18.83μg/m³
PM10
24.68ppb
O3
0.40ppb
SO2
2.89ppb
NO2
0.17ppm
CO
AQI 31
Good
3.65μg/m³
PM2.5
10.44μg/m³
PM10
33.53ppb
O3
0.18ppb
SO2
1.42ppb
NO2
0.12ppm
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 08:00:00 on 2026-08-13.
In the last 24 hours, the best air quality in Leicester, Massachusetts was observed at 04:00:00 on 2026-08-14.
As of now, the AQI in Leicester, Massachusetts is 37, 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 4.192 μg/m3.
The PM10 concentration in Leicester, Massachusetts is 17.435 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Leicester, Massachusetts is 0.139 ppm.
Currently, Leicester, Massachusetts has a sulfur dioxide (SO2) concentration of 0.305 ppb.
The current ozone (O3) level in Leicester, Massachusetts at the moment is 39.967 ppm.
Nitrogen dioxide (NO2) level in Leicester, Massachusetts at the moment is 1.361 ppb.
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