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)
42
Good
Leicester, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
3.53 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
12.54 μg/m³
0
55
155
255
425
605+
45.04 ppb
0
55
71
86
201
201+
0.23 ppb
0
36
76
186
605
1005+
2.08 ppb
0
54
101
361
1250
2050+
0.20 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Leicester, Massachusetts
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AQI 42
Good
3.84μg/m³
PM2.5
12.86μg/m³
PM10
45.20ppb
O3
0.27ppb
SO2
2.42ppb
NO2
0.20ppm
CO
AQI 42
Good
3.96μg/m³
PM2.5
11.39μg/m³
PM10
45.07ppb
O3
0.18ppb
SO2
1.69ppb
NO2
0.20ppm
CO
AQI 42
Good
4.39μg/m³
PM2.5
10.03μg/m³
PM10
45.08ppb
O3
0.10ppb
SO2
1.02ppb
NO2
0.20ppm
CO
AQI 42
Good
3.83μg/m³
PM2.5
11.76μg/m³
PM10
45.08ppb
O3
0.20ppb
SO2
1.82ppb
NO2
0.20ppm
CO
AQI 43
Good
4.31μg/m³
PM2.5
9.91μg/m³
PM10
46.39ppb
O3
0.27ppb
SO2
2.48ppb
NO2
0.20ppm
CO
AQI 42
Good
4.18μg/m³
PM2.5
10.64μg/m³
PM10
45.09ppb
O3
0.17ppb
SO2
1.60ppb
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 09:00:00 on 2026-03-29.
In the last 24 hours, the best air quality in Leicester, Massachusetts was observed at 03:00:00 on 2026-03-29.
As of now, the AQI in Leicester, Massachusetts is 42, 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 3.531 μg/m3.
The PM10 concentration in Leicester, Massachusetts is 12.54 μg/m3 at the moment.
The current carbon monoxide (CO) concentration in Leicester, Massachusetts is 0.198 ppm.
Currently, Leicester, Massachusetts has a sulfur dioxide (SO2) concentration of 0.233 ppb.
The current ozone (O3) level in Leicester, Massachusetts at the moment is 45.036 ppm.
Nitrogen dioxide (NO2) level in Leicester, Massachusetts at the moment is 2.076 ppb.
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