Air quality in Leonessa, Lazio, Italy today

Mr. Duck’s Air Quality Score

Good air today for Leonessa, Lazio, Italy

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality in Leonessa today is classified as Good. The main pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 3.0 and a PM10 reference value of 5.0, based on seven valid observations collected via OpenAQ.

Overall conditions meet the criteria for the Good category according to the latest assessment. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The OpenAQ feed for Leonessa in Lazio supplies data on seven measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), total nitrogen oxides (NOX), ozone (O₃), particulate matter 10 µm or less (PM10), fine particulate matter 2.5 µm or less (PM2.5) and sulphur dioxide (SO₂). The city’s monitoring network contributes two stations, which together generate nine recent data rows. Freshness is mixed: seven of those rows were recorded within the last week, while the remaining two are older than seven days. The newest timestamps appear on 2026‑02‑09 03:00 UTC for NO₂ and O₃, and on 2026‑02‑09 00:00 UTC for NO, NOX, PM10, PM2.5 and SO₂; the PM measurements were last updated a day earlier, on 2026‑02‑08 00:00 UTC.

Across the pollutants the observed values vary considerably. NO₂ shows a minimum of 2 µg/m³, a median of 29 µg/m³ and a maximum of 56 µg/m³, with the 10th percentile at 7.4 µg/m³ and the 90th percentile at 50.6 µg/m³, indicating a fairly wide spread in recent readings. O₃ ranges from 23 to 68 µg/m³ (median 45.5 µg/m³), again with a broad distribution (10th percentile 27.5 µg/m³, 90th percentile 63.5 µg/m³). In contrast, the other gases are essentially constant in the available rows: NO is recorded at 0 µg/m³, NOX at 1 µg/m³, PM10 at 5 µg/m³, PM2.5 at 3 µg/m³ and SO₂ at 0.1 µg/m³.

Overall the dataset provides a recent snapshot for most pollutants, especially NO₂ and O₃, but coverage is uneven: while nitrogen oxides and particulates are represented by single static values, ozone and nitrogen dioxide exhibit notable variability. Because some rows are older than a week, conditions in Leonessa can still differ across locations and times beyond what the current numbers capture.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The data shown for Leonessa reflects seven valid measurements and was refreshed recently, with the latest update recorded on 2026‑02‑09 at 03:00 UTC, meaning it is updated within three days. This snapshot provides a current view of ambient air quality, but conditions can differ across neighborhoods and change throughout the day, so local variations may not be captured in these figures.

OpenAQ station rows