Worst air pollution Alton, today and tomorrow

On 20 September 2026, overall air quality in Alton is fair. AQI is the main air quality indicator at 39.0/100. Pollution peaks around 10:00 PM (NO2: 39.0/100).

On 21 September 2026, air quality conditions in Alton will be worse than today, with AQI forecast at moderate at 49.1/100. Pollution peaks around 8:00 PM (NO2: 49.1/100).

Here's the thing about Alton: air quality has a clear seasonal rhythm. In summer, ozone can build up on sunny afternoons, though windier, warmer weather usually helps clear traffic-related pollution faster than in winter. In deep winter, a lack of wind lets M40 traffic fumes and woodsmoke settle instead of blowing through. Spring and autumn don't usually cause much concern, sitting comfortably between winter's peak and summer's ozone spikes.

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.

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.