Air quality in Horsham, England, United Kingdom today

Mr. Duck’s Air Quality Score

Good air today for Horsham, England, United Kingdom

⚠️ 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 Horsham today is classified as Good. The primary pollutant measured is PM2.5 (fine particles).

Measurements from six valid monitoring points show a PM2.5 reference value of 6.0 and a PM10 reference value of 9.0, indicating that the concentrations are within the limits associated with the Good category. Data is shown via OpenAQ. 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 current dataset for Horsham contains measurements from five monitoring sites and a total of fourteen individual data rows. Six air‑quality variables are represented: nitrogen dioxide (NO₂), particulate matter 1 µm (PM₁), PM₂.₅, PM₁₀, relative humidity, temperature and the particle count labelled UM003. For NO₂, PM₁₀ and PM₂.₅ the most recent values were recorded on 2026‑02‑10 at 20:00 UTC, while the remaining four variables have no timestamp information available, meaning their last update time is unknown.

Across the three pollutants with recent updates, the observed concentrations span a modest range. NO₂ values range from a low of 4.6 µg/m³ to a high of 30.1 µg/m³, with a median around 15 µg/m³; PM₁₀ varies between 6.1 and 9.0 µg/m³, median 6.2 µg/m³; and PM₂.₅ is recorded from roughly 3.8 to 6.0 µg/m³, median 4.5 µg/m³. The tenth‑percentile figures sit near the minima for each pollutant, while the ninetieth percentiles approach the maxima, indicating that most recent readings cluster toward the lower and upper ends of their respective ranges.

In contrast, PM₁, relative humidity, temperature and UM003 each have a single row with no date stamp, so their freshness cannot be assessed. This uneven coverage means that while recent information is available for three key pollutants, the overall picture of air quality in Horsham is incomplete; conditions can differ across locations and times, especially for the variables lacking up‑to‑date data.

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 Horsham reflects six valid measurements and is refreshed regularly, having been updated within the past three days (last update: 2026‑02‑10T20:00:00+00:00). This snapshot provides a current view of air quality across the city, but conditions can differ by specific location and time of day, so values may vary locally.

OpenAQ station rows