Worst air pollution Boston, today and tomorrow

Today (18 July): Air quality in Boston is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 56.1/100).
Tomorrow (19 July 2026): Air quality in Boston is medium. All pollutants stay as today. Pollution peaks around 1:00 PM (O3: 59.4/100). 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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Boston's air quality reflects the northeastern US regional pollution burden, with vehicle emissions from the dense highway network combining with upwind sources to elevate summer ozone across the metro area. The harbour and Charles River corridors provide natural ventilation, while the Blue Hills and coastal sea breezes improve conditions on many days.

Today - 18 July | Pollution peaks at 13:00

AQI:

Medium

56.1/100

PM2.5 (fine particles):

Good

13.1/100

PM10 (coarse particles):

Good

6.3/100

NO2 (nitrogen dioxide):

Good

4.6/100

O3 (ozone):

Medium

56.1/100

SO2 (sulfur dioxide):

Good

0.9/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.6/100

PM1 (ultrafine particles):

Good

14.5/100

Levels show the poorest local air quality during the day

Tomorrow - 19 July | Pollution peaks at 13:00

AQI:

Medium

59.4/100

PM2.5 (fine particles):

Good

11.8/100

PM10 (coarse particles):

Good

8.1/100

NO2 (nitrogen dioxide):

Good

6.4/100

O3 (ozone):

Medium

59.4/100

SO2 (sulfur dioxide):

Good

0.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

7.7/100

PM1 (ultrafine particles):

Good

13.8/100

Pollen forecast in Boston

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Air quality forecasts for neighbourhoods and landmarks in Boston

Sports venues in Boston

Frequently Asked Questions

Is air quality bad in Boston right now?

On 18 July 2026, overall air quality in Boston is medium. AQI is the main air quality indicator at 56.1/100. Pollution peaks around 1:00 PM (O3: 56.1/100).

Will air quality be worse tomorrow in Boston?

On 19 July 2026, air quality conditions in Boston will be similar to today, with AQI forecast at medium at 59.4/100. Pollution peaks around 1:00 PM (O3: 59.4/100).

When is air pollution at its worst in Boston?

Boston sees air quality change through the year. Typically, frequent frontal systems in spring and fall usually keep the air cleanest then, while summer heat and regional haze drifting up from the Midwest and South drive ozone spikes. Coastal sea breezes can offer some relief from inland summer ozone buildup.

Are air quality levels in Boston 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.

Why doesn’t the forecast always reflect wildfire impacts?

Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.

During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.

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Data provided by Airmine — Last update: 18 July 2026 at 21:30 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