Worst air pollution Ljubljana, today and tomorrow
Today (20 September): Air quality in Ljubljana is moderate. AQI, PM2.5, NO2, and PM1 are moderate; PM10 is fair; O3, SO2, CO, and HCHO are good. Pollution peaks around 8:00 AM (PM2.5: 45.4/100).
Tomorrow (21 September 2026): Air quality in Ljubljana is moderate. PM2.5 decreases to fair; PM1 decreases to fair; all other pollutants stay as today. Pollution peaks around 8:00 PM (NO2: 46.9/100). 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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Ljubljana's air quality faces significant winter challenges, with the city's enclosed Ljubljana basin surrounded by the Julian Alps, Kamnik-Savinja Alps, and Kočevski Rog ridgelines creating one of central Europe's most pronounced topographic pollution traps. Residential wood burning and vehicle traffic on the A1 motorway generate elevated PM2.5 under frequent winter inversions, while summer conditions are considerably better with reasonable Alpine ventilation.
Today - 20 September | Pollution peaks at 08:00
AQI:
Moderate
45.4/100
PM2.5 (fine particles):
Moderate
45.4/100
PM10 (coarse particles):
Fair
33.1/100
NO2 (nitrogen dioxide):
Moderate
45.0/100
O3 (ozone):
Good
17.7/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.9/100
HCHO (formaldehyde):
Good
10.6/100
PM1 (ultrafine particles):
Moderate
41.7/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 20:00
AQI:
Moderate
46.9/100
PM2.5 (fine particles):
Fair
39.1/100
PM10 (coarse particles):
Fair
22.2/100
NO2 (nitrogen dioxide):
Moderate
46.9/100
O3 (ozone):
Good
15.4/100
SO2 (sulfur dioxide):
Good
0.9/100
CO (carbon monoxide):
Good
0.8/100
HCHO (formaldehyde):
Good
10.8/100
PM1 (ultrafine particles):
Fair
30.3/100
Pollen forecast in Ljubljana
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Frequently Asked Questions
Is air quality bad in Ljubljana right now?
On 20 September 2026, overall air quality in Ljubljana is moderate. AQI is the main air quality indicator at 45.4/100. Pollution peaks around 8:00 AM (PM2.5: 45.4/100).
Will air quality be worse tomorrow in Ljubljana?
On 21 September 2026, air quality conditions in Ljubljana will be similar to today, with AQI forecast at moderate at 46.9/100. Pollution peaks around 8:00 PM (NO2: 46.9/100).
When is air pollution at its worst in Ljubljana?
Residents in Ljubljana are likeliest to notice reduced air quality when local combined tree and grass pollen peaks, or due to the city's enclosed Ljubljana basin surrounded by the Julian Alps, Kamnik-Savinja Alps, and Kočevski Rog ridgelines; a change of season or a spell of wind usually clears things up again.
Are air quality levels in Ljubljana 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.
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Data provided by Airmine — Last update: 20 September 2026 at 20:27 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.
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