Worst air pollution Diagonal Mar - Barcelona, today and tomorrow
Today (20 September): Air quality in Diagonal Mar is moderate. AQI, PM2.5, and NO2 are moderate; PM10, O3, and PM1 are fair; SO2, CO, and HCHO are good. Pollution peaks around 1:00 AM (PM2.5: 43.8/100).
Tomorrow (21 September 2026): Air quality in Diagonal Mar is moderate. All pollutants stay as today. Pollution peaks around 10:00 PM (NO2: 52.0/100). Airmine updates local air quality forecasts four times daily.
Get the full experience in the Airmine app.
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Follow your pollen exposure and performance with the free Airmine–Strava integration. See your pollen and air quality exposure for every Strava activity.
In Diagonal Mar, construction dust and port and shipping emissions have the largest effect on air quality. Levels vary sharply between the busy centre and quieter residential districts. Low-emission zone restrictions in the centre have reduced traffic-related pollution somewhat.
Today - 20 September | Pollution peaks at 01:00
AQI:
Moderate
43.8/100
PM2.5 (fine particles):
Moderate
43.8/100
PM10 (coarse particles):
Fair
24.8/100
NO2 (nitrogen dioxide):
Moderate
41.1/100
O3 (ozone):
Fair
22.4/100
SO2 (sulfur dioxide):
Good
2.8/100
CO (carbon monoxide):
Good
0.7/100
HCHO (formaldehyde):
Good
10.4/100
PM1 (ultrafine particles):
Fair
27.3/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 22:00
AQI:
Moderate
52.0/100
PM2.5 (fine particles):
Moderate
42.7/100
PM10 (coarse particles):
Fair
22.3/100
NO2 (nitrogen dioxide):
Moderate
52.0/100
O3 (ozone):
Fair
25.9/100
SO2 (sulfur dioxide):
Good
3.3/100
CO (carbon monoxide):
Good
0.8/100
HCHO (formaldehyde):
Good
11.0/100
PM1 (ultrafine particles):
Fair
28.1/100
Other Landmarks in Barcelona
Sports venues in Barcelona
Frequently Asked Questions
Is air quality bad in Diagonal Mar right now?
On 20 September 2026, overall air quality in Diagonal Mar is moderate. AQI is the main air quality indicator at 43.8/100. Pollution peaks around 1:00 AM (PM2.5: 43.8/100).
Will air quality be worse tomorrow in Diagonal Mar?
On 21 September 2026, air quality conditions in Diagonal Mar will be similar to today, with AQI forecast at moderate at 52.0/100. Pollution peaks around 10:00 PM (NO2: 52.0/100).
When is air pollution at its worst in Diagonal Mar?
Does air quality in Diagonal Mar vary by season? Winter tends to bring the year's weakest readings, as stagnant, cold air lets heating smoke and vehicle emissions build up rather than clear away. Conditions tend to ease in spring, as more active weather systems bring the wind and rain needed to disperse ground-level pollution. The heat of summer drives up ozone formation, and dry conditions occasionally bring smoke from regional wildfires into the mix. Conditions generally improve through autumn as cooling temperatures reduce ozone formation and returning rains help disperse remaining pollutants. Sea breezes along this stretch of coast generally support air quality, but summer holiday traffic and occasional calima dust events can interrupt that.
Are air quality levels in Diagonal Mar 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.
Why doesn’t the forecast always reflect wildfire impacts?
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.
Want to see air quality forecasts for other cities in Spain?
Check air quality in other popular cities:
Data provided by Airmine — Last update: 20 September 2026 at 14:33 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.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
Get the full experience in the Airmine app.