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)
29
Good
Leominster, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
3.40 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
12.66 μg/m³
0
55
155
255
425
605+
30.89 ppb
0
55
71
86
201
201+
0.45 ppb
0
36
76
186
605
1005+
1.90 ppb
0
54
101
361
1250
2050+
0.19 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Leominster, Massachusetts
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AQI 31
Good
3.46μg/m³
PM2.5
14.59μg/m³
PM10
32.59ppb
O3
0.45ppb
SO2
1.93ppb
NO2
0.20ppm
CO
AQI 31
Good
3.35μg/m³
PM2.5
14.54μg/m³
PM10
33.01ppb
O3
0.45ppb
SO2
1.73ppb
NO2
0.20ppm
CO
AQI 30
Good
3.25μg/m³
PM2.5
9.39μg/m³
PM10
32.44ppb
O3
0.36ppb
SO2
2.07ppb
NO2
0.20ppm
CO
AQI 31
Good
3.18μg/m³
PM2.5
10.59μg/m³
PM10
32.74ppb
O3
0.54ppb
SO2
1.98ppb
NO2
0.20ppm
CO
AQI 29
Good
3.08μg/m³
PM2.5
8.06μg/m³
PM10
30.59ppb
O3
0.55ppb
SO2
2.56ppb
NO2
0.20ppm
CO
AQI 29
Good
3.44μg/m³
PM2.5
14.65μg/m³
PM10
30.56ppb
O3
0.31ppb
SO2
2.30ppb
NO2
0.21ppm
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, 2026-02-11.
The best air quality in Leominster, Massachusetts was observed at 12:00:00 on 2026-02-12.
The air quality in Leominster, Massachusetts right now is Good, with an AQI of 31.
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 3.227 μg/m3.
Leominster, Massachusetts currently has a PM10 concentration of 10.487 μg/m3.
The current carbon monoxide (CO) level in Leominster, Massachusetts is 0.2 ppm.
The current sulfur dioxide (SO2) concentration in Leominster, Massachusetts is 0.447 ppb.
Leominster, Massachusetts currently has an ozone (O3) concentration of 32.792 ppm.
The current level of nitrogen dioxide (NO2) in Leominster, Massachusetts is 2.07 ppb.
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