US AQI (PM2.5) is calculated from NEA’s 24-hour PM2.5 concentration. It is not an official all-pollutant AQI or NowCast.
Each row shows the latest available observation for that region. PSI and PM2.5 can have different observation times. Missing readings stay unavailable.
NEA's Pollutant Standards Index (PSI) combines six air pollutants. The 24-hour PSI describes air quality over the preceding day; it is not an instant measurement of the air outside. Use NEA's official advisories for activity planning.
PM2.5 measures the concentration of fine particles in micrograms per cubic metre (µg/m³). The 1-hour reading reflects more recent changes. It is a concentration, not a PSI score, and PSI categories must not be applied to it.
Readings come from Singapore's National Environment Agency through data.gov.sg. The interactive view checks every five minutes. The observation time is when the measurement was recorded, not when you opened the page. Readings at least two hours old are labelled as older readings. If the source fails, saved observations keep their original dates and are labelled as saved readings.
Haze Monitor is independent of NEA. Regional readings do not describe conditions at an exact address. Singapore PSI and Malaysia API use different calculations and are not interchangeable.
NEA readings and advisories · Singapore Open Data Licence
Neighbourhood pages use their NEA reporting region. Local conditions can differ within a region.
US Air Quality Index (AQI) · PM2.5
PM2.5 · 24-hour average · How this is calculated
Official NEA PSI: 721 Nov 2026, 22:00 SGT
The main number is PM2.5 US AQI calculated from NEA’s 24-hour PM2.5 concentration. It is not an official all-pollutant AQI or NowCast. Official PSI and 1-hour PM2.5 are shown separately. Region readings are not measurements at the illustrated landmark. We check every five minutes and flag readings at least two hours old.
PSI and Malaysia's API use different calculations. PM2.5 is a concentration in µg/m³, not an index. The Marina Bay scene is an illustration, not a live camera view.
Data from data.gov.sg under the Singapore Open Data Licence. See NEA's official advisories for activity planning.
