Open Data Insight of the Day

This report on air quality in Basel for the period of August 1, 2025, is published because the daily maximum concentration of one or more air quality parameters exceeded the 95th percentile of all values measured in August. On this day, the air quality was characterized by various pollutant levels, with some noteworthy observations.

The maximum ozone (O₃) concentration recorded was 83.8 µg/m³, with an average of 52.35 µg/m³. Nitrogen dioxide (NO₂) reached a maximum of 18.1 µg/m³, averaging 7.15 µg/m³. Particulate matter (PM2.5) levels peaked at 27.8 µg/m³, with a mean of 9.10 µg/m³. The particle count (CPC) had a maximum of 12,339.1 particles/cm³, averaging 4,695.80 particles/cm³. Elemental carbon (EC) concentrations were relatively low, with a maximum of 0.5 µg/m³ and an average of 0.22 µg/m³. Solar radiation peaked at 804.2 W/m², with an average of 215.35 W/m². Sulfur dioxide (SO₂) levels were low, with a maximum of 4.3 µg/m³ and an average of 1.20 µg/m³. Nitrogen oxides (NOx) reached a maximum of 19.1 µg/m³, averaging 8.4 µg/m³. Notably, the PM2.5 maximum exceeded typical values for this period.

Comparing these values to historical data since 2018, the average ozone concentration was below the seasonal average of 74.57 µg/m³, and the maximum was also lower than the historical maximum of 166.5 µg/m³. NO₂ levels were within the normal range, with averages slightly above the seasonal average of 6.99 µg/m³ but below the historical maximum of 31.9 µg/m³. PM2.5 levels were slightly above the seasonal average of 8.06 µg/m³, but the maximum was below the historical peak of 33.8 µg/m³. The particle count was below the seasonal average of 6,457.08 particles/cm³, and the maximum was significantly lower than the historical maximum of 28,499.3 particles/cm³. EC levels were typical, aligning with the seasonal average of 0.21 µg/m³. Solar radiation was below the seasonal average of 254.17 W/m². SO₂ levels were above the seasonal average of 0.45 µg/m³, but the maximum was below the historical peak of 4.7 µg/m³. NOx levels were slightly above the seasonal average of 8.07 µg/m³ but well below the historical maximum of 42.7 µg/m³.

In conclusion, the air quality on August 1, 2025, was generally within historical norms, with some pollutants like PM2.5 showing slightly elevated levels compared to typical values for this period. However, no pollutant levels were alarmingly high compared to historical maxima. The elevated PM2.5 levels could be due to specific local activities or weather conditions, which may warrant further investigation. Overall, the air quality did not exhibit any unusual characteristics that deviate significantly from historical patterns.