Worst air pollution Castelldefels, today and tomorrow
Today (16 July): Air quality in Castelldefels is fair. NO2 is fair; AQI and O3 are medium; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 2:00 PM (O3: 58.2/100).
Tomorrow (17 July 2026): Air quality in Castelldefels is fair. PM2.5 increases to fair; all other pollutants stay as today. Pollution peaks around 2:00 PM (O3: 59.5/100). 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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Castelldefels' air quality benefits from its direct Mediterranean coastal position south of Barcelona's El Prat Airport, with consistent sea breezes from the Barcelona Bay providing reliable maritime ventilation. Vehicle traffic on the C-31 and the airport's approaching flight path contribute elevated NOₓ and aviation PM2.5, while the Barcelona Bay sea breeze cycle and the flat delta position generally maintain moderate conditions, though the airport proximity makes Castelldefels one of Catalonia's more aviation-influenced coastal communities.
Today - 16 July | Pollution peaks at 14:00
AQI:
Medium
58.2/100
PM2.5 (fine particles):
Good
18.2/100
PM10 (coarse particles):
Good
11.2/100
NO2 (nitrogen dioxide):
Fair
26.9/100
O3 (ozone):
Medium
58.2/100
SO2 (sulfur dioxide):
Good
4.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
6.9/100
PM1 (ultrafine particles):
Good
12.6/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 14:00
AQI:
Medium
59.5/100
PM2.5 (fine particles):
Fair
21.3/100
PM10 (coarse particles):
Good
12.7/100
NO2 (nitrogen dioxide):
Fair
33.1/100
O3 (ozone):
Medium
59.5/100
SO2 (sulfur dioxide):
Good
4.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
7.7/100
PM1 (ultrafine particles):
Good
16.2/100
Pollen forecast in Castelldefels
View pollen forecastFrequently Asked Questions
Is air quality bad in Castelldefels right now?
On 16 July 2026, overall air quality in Castelldefels is fair. NO2 is the main pollutant at 26.9/100. Pollution peaks around 2:00 PM (O3: 58.2/100).
Will air quality be worse tomorrow in Castelldefels?
On 17 July 2026, air quality conditions in Castelldefels will be similar to today, with NO2 forecast at fair at 33.1/100. Pollution peaks around 2:00 PM (O3: 59.5/100).
When is air pollution at its worst in Castelldefels?
Does air quality in Castelldefels vary by season? Winter high-pressure systems tend to produce the year's worst episodes, as still air traps traffic fumes and heating smoke at ground level. Air quality usually improves through spring, helped by more frequent frontal systems that bring rain and stronger winds to disperse local emissions. Hot, stagnant summer air favours ozone formation, and dry vegetation nearby occasionally adds wildfire smoke to the mix during peak heat. By late autumn, air quality is usually back to more moderate levels, though the first cold snaps can bring an early hint of winter's traffic and heating pollution. This Mediterranean location benefits from regular sea breezes, though summer's higher traffic volumes and occasional Saharan dust events can offset that.
Are air quality levels in Castelldefels 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