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)
31
Good
Leicester, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
3.10 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
8.68 μg/m³
0
55
155
255
425
605+
33.69 ppb
0
55
71
86
201
201+
0.27 ppb
0
36
76
186
605
1005+
2.20 ppb
0
54
101
361
1250
2050+
0.19 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Leicester, Massachusetts
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AQI 29
Good
3.09μg/m³
PM2.5
8.56μg/m³
PM10
30.68ppb
O3
0.26ppb
SO2
1.99ppb
NO2
0.20ppm
CO
AQI 28
Good
2.69μg/m³
PM2.5
6.37μg/m³
PM10
29.87ppb
O3
0.29ppb
SO2
1.98ppb
NO2
0.20ppm
CO
AQI 29
Good
2.60μg/m³
PM2.5
5.03μg/m³
PM10
30.85ppb
O3
0.30ppb
SO2
2.00ppb
NO2
0.20ppm
CO
AQI 28
Good
2.71μg/m³
PM2.5
6.64μg/m³
PM10
29.68ppb
O3
0.28ppb
SO2
1.92ppb
NO2
0.20ppm
CO
AQI 30
Good
2.83μg/m³
PM2.5
9.43μg/m³
PM10
31.75ppb
O3
0.25ppb
SO2
2.18ppb
NO2
0.19ppm
CO
AQI 28
Good
2.60μg/m³
PM2.5
5.78μg/m³
PM10
30.08ppb
O3
0.30ppb
SO2
2.12ppb
NO2
0.20ppm
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 02:00:00 on 2026-02-12.
As of now, the AQI in Leicester, Massachusetts is 31, 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 3.101 μg/m3.
The PM10 concentration in Leicester, Massachusetts is 8.68 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Leicester, Massachusetts is 0.191 ppm.
Currently, Leicester, Massachusetts has a sulfur dioxide (SO2) concentration of 0.267 ppb.
The current ozone (O3) level in Leicester, Massachusetts at the moment is 33.686 ppm.
Nitrogen dioxide (NO2) level in Leicester, Massachusetts at the moment is 2.203 ppb.
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