🇸🇬Singapore

Singapore (about 745 km²) is a compact island city-state lying just north of the equator at 1.3°N, situated at the southern tip of the Malay Peninsula between the South China Sea and the Strait of Malacca, exhibiting a textbook equatorial tropical rainforest climate (Köppen Af).

The republic comprises the main Singapore Island (approximately 50 km east-west by 27 km north-south) plus dozens of offshore islands and islets, with topography ranging from sea level to the modest 164 m peak at Bukit Timah Hill, creating minimal elevation-driven climate variation.

The climate is characterized by uniformly high temperatures (23–32°C year-round), oppressive humidity averaging above 80% with little seasonal fluctuation, and abundant rainfall (2,200–2,700 mm annually) distributed across all months with no true dry season, though northeast monsoon (November–March) and southwest monsoon (June–September) phases modulate intensity.

The southwest monsoon and inter-monsoon months (April–November) bring the most frequent Sumatra squalls (intense thunderstorm lines propagating eastward from Sumatra), usually before dawn or in the early morning, capable of dumping heavy rain within one to two hours. The urban heat island effect intensifies nighttime temperatures by up to 7°C compared to vegetated areas.

Singapore faces intensifying heat, transboundary air pollution, and accelerating sea-level rise. The 2015 Southeast Asian haze crisis from Indonesian forest fires brought a Pollutant Standards Index exceeding 300 (hazardous level) in late September, forcing school closures and increasing haze-related respiratory illness.

Flash flooding repeatedly threatens the city; June 2010 Orchard Road floods delivered about 100 mm in two hours, exposing infrastructure vulnerabilities. May 2023 brought extreme heat, with temperatures reaching 37.0°C on 13 May, equalling Singapore's all-time record from April 1983. Sea-level rise increasingly threatens Singapore's low-lying coastal areas and reclaimed land.

Our archive covers 26 Singaporean cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Sembawang Estate, with average highs around 29.5°C, while Bukit Panjang New Town has the coldest January nights, with average lows near 23.4°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1°C.