Worst air pollution Dorchester, today and tomorrow

Today (16 July): Air quality in Dorchester is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 5:00 PM (O3: 29.1/100).
Tomorrow (17 July 2026): Air quality in Dorchester is fair. NO2 increases to fair; all other pollutants stay as today. Pollution peaks around 8:00 PM (NO2: 24.7/100). 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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The M40 generates consistent traffic-related NO₂ and PM2.5, particularly during peak commuting hours. Dorchester's air quality reflects its position within Dorset, with local traffic and the town's built-up core as the main contributors. Prevailing westerlies usually ensure decent dispersal, so levels generally stay within the moderate range typical of UK towns.

Today - 16 July | Pollution peaks at 17:00

AQI:

Fair

29.1/100

PM2.5 (fine particles):

Good

8.3/100

PM10 (coarse particles):

Good

3.0/100

NO2 (nitrogen dioxide):

Good

11.2/100

O3 (ozone):

Fair

29.1/100

SO2 (sulfur dioxide):

Good

1.1/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.2/100

PM1 (ultrafine particles):

Good

6.3/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 20:00

AQI:

Fair

24.7/100

PM2.5 (fine particles):

Good

12.0/100

PM10 (coarse particles):

Good

4.0/100

NO2 (nitrogen dioxide):

Fair

24.7/100

O3 (ozone):

Fair

23.0/100

SO2 (sulfur dioxide):

Good

1.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

3.5/100

PM1 (ultrafine particles):

Good

11.6/100

Pollen forecast in Dorchester

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Frequently Asked Questions

Is air quality bad in Dorchester right now?

On 16 July 2026, overall air quality in Dorchester is fair. AQI is the main air quality indicator at 29.1/100. Pollution peaks around 5:00 PM (O3: 29.1/100).

Will air quality be worse tomorrow in Dorchester?

On 17 July 2026, air quality conditions in Dorchester will be similar to today, with AQI forecast at fair at 24.7/100. Pollution peaks around 8:00 PM (NO2: 24.7/100).

When is air pollution at its worst in Dorchester?

Here's the thing about Dorchester: air quality has a clear seasonal rhythm. Come winter, NO₂ and PM2.5 usually creep up, as heating and calmer air let M40 traffic emissions linger rather than disperse. Warmer months swap one problem for another — less smoke and heating pollution, but more ozone on the sunniest days. Spring and autumn tend to be the calmer, more moderate stretches by comparison.

Are air quality levels in Dorchester 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