Air quality in Westzaan, North Holland, Netherlands today

Mr. Duck’s Air Quality Score

Moderate air today for Westzaan, North Holland, Netherlands

⚠️ 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 Westzaan today is classified as Moderate. The primary pollutant identified is PM2.5, fine particulate matter measured against a reference value of 11.5 µg/m³. Data from four valid measurements are shown via OpenAQ.

PM10 levels are also reported with a reference value of 16.3 µg/m³. 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 Westzaan air‑quality record draws on a single monitoring station, so each pollutant is represented by one row of data. The dataset includes five measured species – nitrogen monoxide (NO), nitrogen dioxide (NO₂), particulate matter ≤10 µm (PM₁₀), particulate matter ≤2.5 µm (PM₂.₅) and sulphur dioxide (SO₂). Freshness varies across the suite: NO₂, PM₁₀, PM₂.₅ and SO₂ were all last updated on 2026‑02‑10 at 21:00 UTC, while the NO reading is much older, dated 2024‑03‑25 at 22:00 UTC.

For the four recent pollutants the observed values span modest ranges. NO₂ recorded a maximum of 39 µg/m³ and a minimum of 15 µg/m³, with a median of 27 µg/m³; PM₁₀ varied from 9.4 to 16.3 µg/m³ (median ≈ 12.9 µg/m³); PM₂.5 ranged between 4.8 and 11.5 µg/m³ (median ≈ 8.2 µg/m³); SO₂ was low, from 1.0 to 1.5 µg/m³ (median ≈ 1.25 µg/m³). The 10th‑percentile values sit close to the minima for each pollutant, while the 90th‑percentile values approach their respective maxima, indicating a fairly tight distribution during the recent measurement window.

The NO data are effectively missing – all statistical fields contain the placeholder -999.0 µg/m³ and the entry is flagged as “Old data”. Consequently, any assessment of nitrogen monoxide levels in Westzaan must rely on other sources. Overall, the city’s air‑quality picture is based on one recent snapshot for four pollutants and an outdated record for NO, so conditions can differ across neighborhoods and times not captured by this limited set.

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 Westzaan reflects four valid measurements and was updated within three days, with the latest refresh recorded at 2026‑02‑10 21:00 UTC. These values provide a recent snapshot of ambient conditions but represent only limited sampling points; air quality can differ across neighborhoods and change throughout the day, so local variations may not be captured in this overview.

OpenAQ station rows