Worst air pollution Casco Viejo - Bilbao, today and tomorrow

On 30 August 2026, overall air quality in Casco Viejo is fair. AQI is the main air quality indicator at 25.0/100. Pollution peaks around 3:00 PM (O3: 25.0/100).

On 31 August 2026, air quality conditions in Casco Viejo will be better than today, with AQI forecast at good at 19.9/100. Pollution peaks around 5:00 PM (O3: 19.9/100).

When is air quality typically worst in Casco Viejo? Cold, windless spells in December and January are usually when conditions dip most, as heating emissions and traffic fumes accumulate under a stable atmosphere. Spring is typically when conditions begin improving, as increasing wind speeds help disperse traffic emissions before they can accumulate. Summer's combination of intense sun and high temperatures makes ozone the main concern, occasionally compounded by wildfire smoke during dry, windy spells. Autumn usually sees a steady return to cleaner conditions as the ozone-favouring heat of summer fades and rainfall picks up. The Atlantic north's frequent rain and strong onshore winds generally keep year-round levels lower than in the drier interior and south.

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.