Stay updated with real-time air quality in Leominster, 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)
30
Good
Leominster, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
4.22 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
15.41 μg/m³
0
55
155
255
425
605+
32.20 ppb
0
55
71
86
201
201+
0.48 ppb
0
36
76
186
605
1005+
11.28 ppb
0
54
101
361
1250
2050+
0.16 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Leominster, Massachusetts
Leominster, Massachusetts
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AQI 35
Good
3.87μg/m³
PM2.5
12.04μg/m³
PM10
37.65ppb
O3
0.45ppb
SO2
11.18ppb
NO2
0.18ppm
CO
AQI 35
Good
4.43μg/m³
PM2.5
15.70μg/m³
PM10
37.54ppb
O3
0.54ppb
SO2
13.46ppb
NO2
0.18ppm
CO
AQI 35
Good
3.66μg/m³
PM2.5
13.10μg/m³
PM10
38.47ppb
O3
0.45ppb
SO2
15.14ppb
NO2
0.21ppm
CO
AQI 34
Good
4.28μg/m³
PM2.5
15.81μg/m³
PM10
37.34ppb
O3
0.59ppb
SO2
14.12ppb
NO2
0.17ppm
CO
AQI 36
Good
4.50μg/m³
PM2.5
18.42μg/m³
PM10
38.64ppb
O3
0.53ppb
SO2
14.04ppb
NO2
0.18ppm
CO
AQI 31
Good
4.15μg/m³
PM2.5
13.61μg/m³
PM10
33.76ppb
O3
0.35ppb
SO2
8.39ppb
NO2
0.18ppm
CO
The air quality data for Massachusetts, USA is gathered from reliable sources such as satellites and monitoring stations, adhering to US EPA guidelines. With the help of advanced algorithms and machine learning, factors like traffic and population density are analyzed to deliver accurate and dependable results.
Source: Ambee Data Sources
Air quality updates for Leominster, Massachusetts are available every hour.
Leominster, Massachusetts experienced its worst air quality at 02:00:00, 2026-05-14.
The best air quality in Leominster, Massachusetts was observed at 02:00:00 on 2026-05-13.
The air quality in Leominster, Massachusetts right now is Good, with an AQI of 30.
In Leominster, Massachusetts, O3 is the most frequently found pollutant.
When air quality in Leominster, Massachusetts is compromised, staying indoors and wearing a mask can reduce health risks.
Leominster, Massachusetts currently has a PM2.5 concentration of 4.221 μg/m3.
Leominster, Massachusetts currently has a PM10 concentration of 15.407 μg/m3.
The current carbon monoxide (CO) level in Leominster, Massachusetts is 0.163 ppm.
The current sulfur dioxide (SO2) concentration in Leominster, Massachusetts is 0.484 ppb.
Leominster, Massachusetts currently has an ozone (O3) concentration of 32.196 ppm.
The current level of nitrogen dioxide (NO2) in Leominster, Massachusetts is 11.275 ppb.
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