Worst air pollution Sant Martí - Barcelona, today and tomorrow

On 19 July 2026, overall air quality in Sant Martí is fair. PM2.5 is the main pollutant at 34.0/100. Pollution peaks around 3:00 PM (O3: 51.3/100).

On 20 July 2026, air quality conditions in Sant Martí will be worse than today, with AQI forecast at poor at 60.2/100. Pollution peaks around 3:00 PM (O3: 60.2/100).

What time of year has the cleanest air in Sant Martí? Air quality often reaches its yearly low in the depths of winter, when still, cold air holds local emissions from traffic and heating close to ground level. Spring generally sees a gradual recovery, driven by more frequent rain showers and stronger breezes that prevent pollutants from settling. Summer brings its own challenge in the form of ground-level ozone, which forms readily under strong sunshine and high temperatures, particularly during heatwaves. Autumn usually sees a steady return to cleaner conditions as the ozone-favouring heat of summer fades and rainfall picks up. The Mediterranean coast's sea breezes generally help disperse pollution, though summer tourism traffic and occasional Saharan dust can still push levels up.

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.