Worst air pollution Leominster, today and tomorrow
Today (16 July): Air quality in Leominster is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 36.3/100).
Tomorrow (17 July 2026): Air quality in Leominster is fair. All pollutants stay as today. Pollution peaks around 1:00 PM (O3: 38.8/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Leominster's air quality in Massachusetts reflects the Nashua River valley in north-central Massachusetts, with vehicle emissions from Route 2 and I-190 and surrounding manufacturing legacy contributing local sources. The surrounding Central Massachusetts uplands create modest topographic variation, while the broader New England regional airshed contributes limited upwind urban sources and the Nashua River valley provides some natural ventilation on southerly days.
Today - 16 July | Pollution peaks at 13:00
AQI:
Fair
36.3/100
PM2.5 (fine particles):
Good
12.1/100
PM10 (coarse particles):
Good
9.7/100
NO2 (nitrogen dioxide):
Good
6.0/100
O3 (ozone):
Fair
36.3/100
SO2 (sulfur dioxide):
Good
1.0/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.1/100
PM1 (ultrafine particles):
Good
5.4/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 13:00
AQI:
Fair
38.8/100
PM2.5 (fine particles):
Good
10.0/100
PM10 (coarse particles):
Good
8.1/100
NO2 (nitrogen dioxide):
Good
7.0/100
O3 (ozone):
Fair
38.8/100
SO2 (sulfur dioxide):
Good
1.2/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.0/100
PM1 (ultrafine particles):
Good
5.9/100
Pollen forecast in Leominster
View pollen forecastFrequently Asked Questions
Is air quality bad in Leominster right now?
On 16 July 2026, overall air quality in Leominster is fair. AQI is the main air quality indicator at 36.3/100. Pollution peaks around 1:00 PM (O3: 36.3/100).
Will air quality be worse tomorrow in Leominster?
On 17 July 2026, air quality conditions in Leominster will be similar to today, with AQI forecast at fair at 38.8/100. Pollution peaks around 1:00 PM (O3: 38.8/100).
When is air pollution at its worst in Leominster?
Air quality across Leominster rises and falls with the seasons — the cleanest conditions typically arrive with the more unsettled weather of spring and autumn, whereas the combination of local heat and imported regional haze peaks during summer. Coastal sea breezes can offer some relief from inland summer ozone buildup.
Are air quality levels in Leominster based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
For long term forecasts and maps, see the Airmine app