Physical Geography and Climate

<h1>Physical Geography and Climate</h1> <p>Singapore is a small equatorial island country at the southern end of the Malay Peninsula, separated from Peninsular Malaysia by the Straits of Johor and from Indonesia's Riau Islands by the Singapore Strait. Its physical setting explains many national constraints: limited land, dependence on regional connections, intense rainfall, coastal exposure, and an urban form that puts infrastructure, reservoirs, industry, nature, and housing into close competition. As at December 2025, Singapore's official land area was 744.3 km², a value that changes as <a href="/en/knowledge/article/sgkb.geography-urban-planning.land-reclamation">reclamation</a> and cadastral surveys alter the measured shoreline (<a href="https://www.singstat.gov.sg/find-data/search-by-theme/society/environment/latest-data">SingStat, accessed Aug 2026</a>).</p> <h2>Location, islands, and dimensions</h2> <p>Singapore lies between 1°09′ and 1°29′ north and 103°36′ and 104°25′ east, about 137 kilometres north of the Equator. The main island extends roughly 49 kilometres east to west and 28 kilometres north to south, with numerous surrounding islets and artificial landforms (<a href="https://www.singstat.gov.sg/find-data/search-by-theme/society/environment/latest-data">SingStat, accessed Aug 2026</a>). Jurong Island is an amalgamation of former islands supporting the energy and chemicals sector, while Pulau Ubin retains a rural landscape and Pulau Tekong is primarily used for military training — see <a href="/en/knowledge/article/sgkb.geography-urban-planning.offshore-islands">offshore islands</a> for recreation, conservation, and access across Singapore's offshore islands.</p> <p>Singapore's position beside the Strait of Malacca–Singapore Strait route made it valuable as a port and remains central to its trade, maritime, and security strategy. The country has no natural hinterland: cross-border water, energy, food, labour, and transport links connect the island to Malaysia, Indonesia, and wider shipping and aviation networks. Its compact dimensions also mean that weather is broadly national, but rainfall can vary sharply between locations during a single thunderstorm.</p> <h2>Relief, geology, and coast</h2> <p>Singapore is generally flat and low-lying. Much of the country is within 15 metres of sea level, and Bukit Timah Hill is the highest natural point at 164 metres (<a href="https://www.singstat.gov.sg/find-data/search-by-theme/society/environment/latest-data">SingStat, accessed Aug 2026</a>). SingStat groups the terrain into a granite-based central hilly area around Bukit Timah, Bukit Panjang, Mandai, and Bukit Batok; a western undulating area including Mount Faber and Pasir Panjang ridges; and an eastern coastal area of alluvium and sediment extending through Katong, Bedok, and Changi.</p> <p>The low relief makes drainage and coastal protection national infrastructure questions rather than local concerns. Rivers are short and heavily engineered; many feed reservoirs that are also parts of Singapore's <a href="/en/knowledge/article/sgkb.environment-sustainability.water-story">water-supply system</a>. Reclamation has straightened or advanced much of the shoreline, creating districts such as Marine Parade and Marina Bay. Around 30% of Singapore's land is below five metres above mean sea level, so rising seas, storm surges, and extreme rainfall are being addressed through drainage, sea walls, polders, and proposals such as Long Island (<a href="https://www.ura.gov.sg/land-planning/master-plan/master-plan-2025/themes/strengthening-urban-resilience/a-flood-resilient-city-and-coast/">URA, accessed Aug 2026</a>).</p> <h2>Equatorial climate</h2> <p>Singapore has a tropical rainforest climate: high and relatively uniform temperatures, high humidity, and rain in every month. At the Changi climate station, the 1991–2020 mean annual rainfall was 2,113.3 mm across an average of 171 rain days. Mean monthly daily maxima ranged from 30.5°C to 32.4°C, mean monthly daily minima from 24.3°C to 25.7°C, and mean 24-hour relative humidity from about 81% to 86% (<a href="https://www.weather.gov.sg/climate-climate-of-singapore/">Meteorological Service Singapore, accessed Aug 2026</a>). These Changi normals are a climate reference, not a promise for every neighbourhood or year.</p> <p>Solar heating, sea breezes, and abundant moisture produce frequent afternoon thunderstorms, while dense development creates local heat differences. Heavy rain can be highly localised: one part of the island may flood while another remains dry. Singapore does not have four temperate seasons or a truly rainless dry season. Air-conditioning, covered walkways, storm drains, shaded greenery, and building orientation are therefore everyday adaptations embedded in <a href="/en/knowledge/article/sgkb.geography-urban-planning.ura-and-master-plan">urban planning</a>.</p> <h2>Critical perspectives: monsoons and hazardous weather</h2> <p>Singapore's year is organised by prevailing winds. The Northeast Monsoon normally runs from December to early March: a wet phase around December and early January can bring multi-day monsoon surges, followed by a relatively dry phase from late January into early March. The Southwest Monsoon from June to September is generally drier and can bring pre-dawn or morning Sumatra squalls—lines of thunderstorms moving east from Sumatra or the Strait of Malacca. Light and variable winds mark inter-monsoon periods around late March–May and October–November, when strong afternoon and evening thunderstorms are common (<a href="https://www.weather.gov.sg/climate-climate-of-singapore/">Meteorological Service Singapore, accessed Aug 2026</a>; <a href="https://www.weather.gov.sg/learn_winds/">MSS winds guide, accessed Aug 2026</a>).</p> <p>Lightning, flash floods, strong gusts, heat, and regional haze are the most consequential weather-related hazards; Singapore is outside the usual tracks of tropical cyclones but can experience their indirect effects. Climate is already changing: annual rainfall since 1980 has increased on a long-term trend despite large year-to-year variation, while temperatures and warm nights have risen (<a href="https://www.weather.gov.sg/climate-past-climate-trends/">Meteorological Service Singapore, accessed Aug 2026</a>). Current weather should always be retrieved from live forecasts rather than inferred from these climatological patterns.</p> <h2>Observed climate snapshot — 2025</h2> <p>The Meteorological Service Singapore reported that <strong>2025 was Singapore's seventh-wettest year since 1980</strong>, with average annual rainfall of <strong>2,984.9 mm</strong>, 18% above the long-term average. That annual figure is an average across <strong>32 stations with continuous rainfall records</strong>, not the Changi station's 2,833.5 mm; the latter was 34% above its own 1991–2020 average. Singapore also recorded its wettest March on record, while June and November were the warmest such months on record. The annual mean temperature was <strong>28.1°C</strong>, joint eighth-warmest in the climate-station record (<a href="https://www.weather.gov.sg/singapore-records-wettest-ever-march-and-hottest-ever-june-and-november-in-2025/">MSS 2025 climate assessment summary, published 23 Mar 2026 and accessed Aug 2026</a>). These are observations for calendar year 2025, not the 1991–2020 climate normals or a forecast for 2026.</p>

简介

自然地理与气候

新加坡是位于马来半岛南端的赤道小岛国,与马来西亚半岛隔柔佛海峡相望,与印度尼西亚廖内群岛隔新加坡海峡相望。其自然地理环境解释了许多国家层面的限制:土地有限、依赖区域联系、降雨强烈、面临海岸风险,而且城市形态使基础设施、水库、工业、自然环境与住宅彼此紧密竞争。截至 2025 年十二月,新加坡官方陆地面积为 744.3 平方 公里;随着填海造地和地籍测量改变海岸线测量结果,这一数值也会变化(新加坡统计局,2026 年八月查阅)。

地理位置、岛屿与尺寸

新加坡位于北纬 1°09′至 1°29′、东经 103°36′至 104°25′之间,距赤道以北约 137 公里。主岛东西向约 49 公里,南北向约 28 公里,周围分布着许多小岛和人工地貌(新加坡统计局,2026 年八月查阅)。裕廊岛由昔日多个岛屿合并而成,支撑能源与化工产业;乌敏岛保留了乡村景观,德光岛则主要用于军事训练。有关新加坡离岸岛屿上的休闲、保育和交通,可参阅离岸岛屿。

新加坡毗邻马六甲海峡—新加坡海峡航线,因此作为港口具有重要价值,并持续在贸易、海事和安全战略中发挥核心作用。该国没有天然腹地:跨境水、能源、食品、劳动力和交通联系将这座岛屿连接至马来西亚、印度尼西亚以及更广泛的航运和航空网络。新加坡幅员紧凑,因此天气大体上具有全国性,但一场雷暴期间不同地点的降雨量可能差异显著。

地势、地质与海岸

新加坡总体平坦且地势低。全国大部分地区海拔在 15 米以内,武吉知马山是最高的天然地点,海拔 164 米(新加坡统计局,2026 年八月查阅)。新加坡统计局将地形分为三类:以花岗岩为基础、围绕武吉知马、武吉班让、万礼和武吉巴督的中部丘陵区;包括花柏山和巴西班让山脊的西部起伏地带;以及由冲积物和沉积物构成、从加东、勿洛延伸至樟宜的东部沿海地区。

地势低平意味着排水和海岸防护是全国基础设施议题,而非地方层面的关切。河流短小且经过大量工程改造;许多河流汇入水库,而水库也是新加坡供水系统的一部分。填海造地拉直或推进了大部分海岸线,形成了马林百列和滨海湾等地区。新加坡约 30%的土地低于平均海平面以上五 米,因此正在通过排水系统、海堤、圩田以及长岛等规划方案,应对海平面上升、风暴潮和极端降雨(市区重建局,2026 年八月查阅)。

赤道气候

新加坡属于热带雨林气候:气温高且相对稳定、湿度高,而且每个月都会降雨。在樟宜气候站,1991–2020 年的年平均降雨量为 2,113.3 毫米,平均每年有 171 个雨日。月平均每日最高气温介于 30.5 °C至 32.4 °C之间,月平均每日最低气温介于 24.3 °C至 25.7 °C之间,24 小时平均相对湿度约为 81%至 86%(新加坡气象署,2026 年八月查阅)。这些樟宜气候平均值是气候参考数据,并不保证每个社区或每一年都符合这些情况。

太阳辐射加热、海风和充沛水汽带来频繁的午后雷暴,而密集开发则造成局部热差异。强降雨可能高度局部化:岛上一处可能发生水灾,另一处却仍然干燥。新加坡没有温带地区的四季,也没有真正无雨的旱季。因此,空调、有盖走道、雨水排水沟、遮荫绿地和建筑朝向,都是融入城市规划的日常适应措施。

关键观点:季风与危险天气

新加坡的年度气候周期由盛行风决定。东北季风通常从十二月持续至三月初:十二月和一月初前后的湿润阶段可能带来持续多日的季风涌;随后,从一月下旬至三月初进入相对干燥阶段。六月至九月的西南季风通常较干燥,也可能带来黎明前或上午出现的苏门答腊飑线——这类雷暴带从苏门答腊或马六甲海峡向东移动。三月下旬至五月以及十月至十一月前后的季风间期,风力微弱且多变,午后和傍晚常有强雷暴(新加坡气象署,2026 年八月查阅;新加坡气象署风向指南,2026 年八月查阅)。

雷电、突发性水灾、强阵风、高温和区域性烟霾是影响最显著的天气相关风险;新加坡位于热带气旋通常路径之外,但可能受到其间接影响。气候已经在变化:自 1980 年以来,尽管年际变化很大,年降雨量仍呈长期上升趋势;气温和暖夜也有所上升(新加坡气象署,2026 年八月查阅)。当前天气应始终通过实时预报获取,而不应根据这些气候规律推断。

已观测气候概况——2025 年

新加坡气象署报告称,2025 年是新加坡自 1980 年以来第七个最潮湿的年份,年平均降雨量为2,984.9 毫米,比长期平均值高 18%。该年度数据是32 个持续记录降雨量的测站的平均值,并非樟宜测站的 2,833.5 毫米;后者比其自身 1991–2020 年平均值高 34%。新加坡还记录了有史以来最潮湿的三月,而六月和十一月则分别创下同月份最暖纪录。年平均气温为28.1 °C,在气候测站记录中并列第八高(新加坡气象署 2025 年气候评估摘要,发表于 2026 年三月 23 日并于 2026 年八月查阅)。这些是 2025 日历年的观测结果,并非 1991–2020 年气候平均值,也不是 2026 年的预报。