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)
58
Moderate
Leominster, Massachusetts
Last updated: ... (Local time)

Good
Fine
Moderate
Poor
Very poor
Hazardous
12.83 μg/m³
0
12.1
35.5
55.5
250.5
500.5+
53.29 μg/m³
0
55
155
255
425
605+
35.76 ppb
0
55
71
86
201
201+
0.52 ppb
0
36
76
186
605
1005+
3.12 ppb
0
54
101
361
1250
2050+
0.14 ppm
0
4.5
9.5
12.5
230.5
50.5+
Pollen Level
Low
Leominster, Massachusetts
Leominster, Massachusetts
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AQI 58
Moderate
12.88μg/m³
PM2.5
34.99μg/m³
PM10
34.94ppb
O3
0.54ppb
SO2
2.05ppb
NO2
0.14ppm
CO
AQI 56
Moderate
12.24μg/m³
PM2.5
53.35μg/m³
PM10
33.27ppb
O3
0.57ppb
SO2
3.09ppb
NO2
0.12ppm
CO
AQI 52
Moderate
9.93μg/m³
PM2.5
35.38μg/m³
PM10
33.63ppb
O3
0.45ppb
SO2
3.28ppb
NO2
0.12ppm
CO
AQI 56
Moderate
11.52μg/m³
PM2.5
46.40μg/m³
PM10
34.67ppb
O3
0.61ppb
SO2
2.92ppb
NO2
0.12ppm
CO
AQI 56
Moderate
12.19μg/m³
PM2.5
50.45μg/m³
PM10
37.07ppb
O3
0.65ppb
SO2
2.16ppb
NO2
0.12ppm
CO
AQI 58
Moderate
12.72μg/m³
PM2.5
52.80μg/m³
PM10
34.70ppb
O3
0.35ppb
SO2
2.02ppb
NO2
0.14ppm
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 06:00:00, 2026-06-29.
The best air quality in Leominster, Massachusetts was observed at 07:00:00 on 2026-06-29.
The air quality in Leominster, Massachusetts right now is Moderate, with an AQI of 58.
In Leominster, Massachusetts, PM2.5 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 12.833 μg/m3.
Leominster, Massachusetts currently has a PM10 concentration of 53.289 μg/m3.
The current carbon monoxide (CO) level in Leominster, Massachusetts is 0.142 ppm.
The current sulfur dioxide (SO2) concentration in Leominster, Massachusetts is 0.521 ppb.
Leominster, Massachusetts currently has an ozone (O3) concentration of 35.755 ppm.
The current level of nitrogen dioxide (NO2) in Leominster, Massachusetts is 3.116 ppb.
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