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)
27
Good
Leicester, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
2.29 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
9.95 μg/m³
0
55
155
255
425
605+
29.48 ppb
0
55
71
86
201
201+
0.28 ppb
0
36
76
186
605
1005+
3.07 ppb
0
54
101
361
1250
2050+
0.21 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Leicester, Massachusetts
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AQI 27
Good
1.73μg/m³
PM2.5
5.71μg/m³
PM10
28.64ppb
O3
0.34ppb
SO2
3.35ppb
NO2
0.21ppm
CO
AQI 27
Good
1.89μg/m³
PM2.5
7.24μg/m³
PM10
29.12ppb
O3
0.38ppb
SO2
4.70ppb
NO2
0.21ppm
CO
AQI 27
Good
1.90μg/m³
PM2.5
7.98μg/m³
PM10
29.39ppb
O3
0.40ppb
SO2
5.97ppb
NO2
0.20ppm
CO
AQI 27
Good
1.90μg/m³
PM2.5
7.13μg/m³
PM10
29.09ppb
O3
0.37ppb
SO2
4.28ppb
NO2
0.21ppm
CO
AQI 26
Good
2.06μg/m³
PM2.5
7.03μg/m³
PM10
28.46ppb
O3
0.37ppb
SO2
3.80ppb
NO2
0.20ppm
CO
AQI 27
Good
1.82μg/m³
PM2.5
7.02μg/m³
PM10
29.10ppb
O3
0.38ppb
SO2
5.22ppb
NO2
0.21ppm
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 03:00:00 on 2026-02-11.
In the last 24 hours, the best air quality in Leicester, Massachusetts was observed at 01:00:00 on 2026-02-12.
As of now, the AQI in Leicester, Massachusetts is 27, 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 1.639 μg/m3.
The PM10 concentration in Leicester, Massachusetts is 4.206 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Leicester, Massachusetts is 0.209 ppm.
Currently, Leicester, Massachusetts has a sulfur dioxide (SO2) concentration of 0.334 ppb.
The current ozone (O3) level in Leicester, Massachusetts at the moment is 28.958 ppm.
Nitrogen dioxide (NO2) level in Leicester, Massachusetts at the moment is 3.339 ppb.
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