Air Quality in Italy: Stable Values in 2025
Data from the National System for Environmental Protection
Limit values for PM10 and PM2.5 have been met across almost the entire country, although exceedances persist in several areas. Nitrogen dioxide levels are decreasing. Extreme heat and lack of precipitation do not improve the ozone situation during summer. The new European Directive sets stricter limits to be achieved by January 1, 2030, requiring additional strategies.
The annual report by SNPA (National System for Environmental Protection) provides a national overview of air quality in the past year. It is a concise report prepared each year by experts from ISPRA and the environmental agencies of Regions and Autonomous Provinces, summarizing data collected from monitoring stations across the country.
Compliance with the annual limit value for PM10 (40 μg/m³ – micrograms per cubic meter) has been recorded in all regions; in 92% of monitoring stations, the daily limit value is also met (50 μg/m³ as a daily average, not to be exceeded on more than 35 days per year). However, critical issues persist in several areas of the country: in the Po Valley, in the Naples–Caserta metropolitan area, and in the Sacco Valley (in the province of Frosinone). Isolated exceedances have also been recorded in the Venafro plain (in the province of Isernia) and in Palermo. Overall, statistical analysis of the 2015–2024 decade shows a significant decrease in the first five years, followed by a period of stability.
It should be noted that periods of winter atmospheric stagnation (low-level thermal inversion, persistent high pressure, lack of precipitation, very weak or absent winds) in some of the country’s most critical areas were frequent and intense in the past year, contributing on several days to exceedances of the daily limit of 50 μg/m³.
As is well known, daily exceedances may in some cases be influenced by natural phenomena, such as ground-level intrusions of dust from desert areas in North Africa, the Middle East, and the Caspian Depression. The assessment of the frequency and intensity of these events, and their contribution to the number of exceedance days in some regions, is currently underway and will be described in the annual air quality reports prepared by the most affected regional environmental agencies (Arpa/Appa) in the coming months.
The annual limit value for PM2.5 (25 μg/m³) is met across almost the entire national territory. For this pollutant, an average reduction of about 14% in annual levels recorded in 2025 is observed compared to the average for the 2015–2024 decade.
The annual limit value for nitrogen dioxide is also met in the vast majority of monitoring stations (99%), although exceedances are recorded at a limited number of stations located in large urban areas near major roadways, in the metropolitan area of Milan, as well as in Genoa, Naples, Catania, and Palermo. The hourly limit value, however, is met everywhere.
Preliminary data appear to confirm the trend observed in the 2015–2024 period, with a marked and progressive reduction in nitrogen dioxide levels across most monitoring stations.