Worst air pollution Williamstown, today and tomorrow
Today (16 July): Air quality in Williamstown is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 12:00 PM (O3: 35.4/100).
Tomorrow (17 July 2026): Air quality in Williamstown is fair. All pollutants stay as today. Pollution peaks around 10:00 AM (O3: 33.6/100). 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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In Williamstown, clean Berkshire mountain air is the main influence on air quality, and among the cleanest air in Massachusetts, aside from occasional haze. Day-to-day conditions in Williamstown can still vary with local weather, wind direction, and time of year. Visitors and residents alike tend to notice the clearest air outside the warmest summer weeks.
Today - 16 July | Pollution peaks at 12:00
AQI:
Fair
35.4/100
PM2.5 (fine particles):
Good
12.3/100
PM10 (coarse particles):
Good
10.6/100
NO2 (nitrogen dioxide):
Good
19.0/100
O3 (ozone):
Fair
35.4/100
SO2 (sulfur dioxide):
Good
1.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.6/100
PM1 (ultrafine particles):
Good
5.5/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 10:00
AQI:
Fair
33.6/100
PM2.5 (fine particles):
Good
11.1/100
PM10 (coarse particles):
Good
8.7/100
NO2 (nitrogen dioxide):
Good
13.8/100
O3 (ozone):
Fair
33.6/100
SO2 (sulfur dioxide):
Good
2.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
3.3/100
PM1 (ultrafine particles):
Good
6.3/100
Pollen forecast in Williamstown
View pollen forecastFrequently Asked Questions
Is air quality bad in Williamstown right now?
On 16 July 2026, overall air quality in Williamstown is fair. AQI is the main air quality indicator at 35.4/100. Pollution peaks around 12:00 PM (O3: 35.4/100).
Will air quality be worse tomorrow in Williamstown?
On 17 July 2026, air quality conditions in Williamstown will be similar to today, with AQI forecast at fair at 33.6/100. Pollution peaks around 10:00 AM (O3: 33.6/100).
When is air pollution at its worst in Williamstown?
Conditions in Williamstown vary noticeably across the seasons. In short, frequent frontal systems in spring and fall usually keep the air cleanest then, whereas the combination of local heat and imported regional haze peaks during summer. Winter cold fronts tend to clear the air quickly, so extended pollution episodes are relatively uncommon.
Are air quality levels in Williamstown 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