About
Where every number on SGWeather comes from
Every reading is shown with its own timestamp and source. Nothing is modelled or estimated unless it says so.
Sources
- Air quality: NEA 1-hour PM2.5 and 24-hour PSI for five regions, with all six pollutant concentrations and sub-indices, hourly, via data.gov.sg (Open Data Licence).
- Rain gauges and weather stations: NEA automatic instruments — rainfall in 5-minute totals from about sixty gauges; air temperature, relative humidity, wind speed and direction from the MSS station network — via data.gov.sg.
- Forecasts: NEA's 2-hour nowcast for 47 areas, the 24-hour forecast and the 4-day outlook, via data.gov.sg. The hourly and seven-day panels are a numerical model (Open-Meteo's blend of ECMWF, GFS and ICON) and are labelled as such; NEA does not publish hourly forecasts.
- Rain radar: the Meteorological Service Singapore 50-km rain-area composite, every five minutes.
- History: NEA's historical hourly PM2.5 and PSI datasets on data.gov.sg (from April 2014, refreshed about monthly), plus SGWeather's own hourly recorder for the most recent 48 hours.
- Maps: OpenStreetMap contributors.
Methodology
Bands and advice follow NEA's published schemes: the 24-hour PSI bands (Good to Hazardous) with the associated health advisory, and the 1-hour PM2.5 bands (Normal, Elevated, High, Very high) with NEA's personal guide.
US EPA AQI is computed from the same NEA concentration with the EPA's current breakpoints, including the PM2.5 table revised in May 2024. It is shown so that visitors used to the US scale — or to apps that use it — can compare. Where NEA's averaging period differs from the EPA definition, the US figure is left blank rather than estimated.
Feels-like is the NWS heat index computed from the nearest station's temperature and humidity; dew point uses the Magnus formula.
Timestamps and lag. Every panel shows the time of the reading it displays. If a feed is older than expected — data.gov.sg's mirror occasionally lags NEA's own site — the stamp turns amber and says so. We never silently substitute an older reading for a newer one.
Ollie and Pango
The two characters on the site are a smooth-coated otter and a Sunda pangolin, both native to Singapore. They carry the readings and the advice; they never replace them — every number next to a mascot is NEA's, with its timestamp.
Independence
SGWeather is an independent site and is not affiliated with NEA, MSS, data.gov.sg or the Singapore Government. Official advisories are at haze.gov.sg and weather.gov.sg.
Contact
Corrections, data questions and partnership enquiries: hello@sgweather.com.