Data from Changi Meteorological Station (S24) — operated by the Meteorological Service Singapore (MSS), located at Upper Changi Road North (lat 1.3678°N, lon 103.9826°E). Updates every minute via api.data.gov.sg · weather.gov.sg.

Note: This is not the WSSS (Singapore Changi Airport ASOS) sensor that Polymarket resolves against. S24 is an MSS surface station located approximately 1.3 km northwest of the WSSS aviation sensor. Both are on airport grounds and typically read within 0.5–1.0°C of each other, but the authoritative Polymarket source remains WSSS via NOAA METAR above.