Due to its geographical location and maritime exposure, Singapore’s climate is characterized by uniform temperature and pressure, high humidity and abundant rainfall. The average temperature is between 25 degrees Celsius and 31 degrees Celsius. Thunderstorms occur on 40% of all days. Relative humidity is in the range of 70% – 80%. April is the warmest month, January is the coolest month and November is the wettest month.

Singapore lies between Malaysia and Indonesia, with a total area of 693 sq km and a coastline of 193 km. It consists of one main island and several other surrounding islets. It is often described as a gently undulating central plateau that contains water catchments and natural reserves. There is a small cluster of hills at the centre, and mangrove swamps along the coast, especially in the northern and western regions. The highest point in Singapore is Bukit Timah (a hill), with a height of 166 m which is situated in the central region of the island. The mainland measures 47 km from east to west and 28 km from north to south.

Geographically, there are three major regions in Singapore. The central hilly region has heavy deposits of granite (Bukit Timah, Bukit Batok, Bukit Panjang and Bukit Mandai). The west and southwestern parts of the island consist of sedimentary rocks, which have formed narrow ridges (Mount Faber Ridge and Pasir Panjang Ridge). The eastern part of Singapore is largely flat and sandy (from Katong to Bedok and Changi). It is also a rain shadow region and as a result receives less rainfall than the western region. The narrow Singapore River meanders through the city, with the Central Business District near its mouth. It boasts of an impressive skyline with many high rise buildings and apartments. This area also houses the shopping hub (Orchard Road), parks and attractive squares.

Over the years Singapore’s landscape has changed due to urbanization. The hilly central region has been levelled, mangrove swamps have been drained and filled, and the islets have been enlarged to set up industrial estates. Three main water reservoirs and their catchment area is what is left of the rain-forests and occupies the central region of the city-state.

As the island lies within 15 meters of sea level, its climate is influenced by the sea and its geographical location. Singapore does not face the danger of earthquakes, volcanoes or typhoons. However, it does experience occasional flash floods in certain low lying regions when there is excessive rainfall.

Climate and Weather Overview
True to its Southeast Asian location, Singapore is characterised by a hot and humid climate. Located just 1 degree north of the equator, it quite naturally enjoys a tropical/equatorial climate. The island does not have clear-cut seasons like summer, spring, autumn and winter. The weather is warm and humid all year round. Rainfall is almost an everyday phenomenon, even during the non-monsoon period. These brief showers are usually quite refreshing, as they provide respite from the sun.

Due to its geographical location and maritime exposure, Singapore’s climate is characterized by uniform temperature and pressure, high humidity and abundant rainfall. The average temperature is between 25 degrees Celsius and 31 degrees Celsius. Thunderstorms occur on 40% of all days. Relative humidity is in the range of 70% – 80%. April is the warmest month, January is the coolest month and November is the wettest month.

Monsoon Characteristics
There is no clear-cut wet or dry season and rain is experienced every single month, usually in the afternoons and early evenings. However, there are two main monsoon seasons in Singapore: Northeast Monsoon Season (December-March) and the Southwest Monsoon Season (June-September).

You would be surprised to know that the Northeast Monsoon has a “wet phase” (December and January) and a “dry phase” (February and March). The wet phase witnesses continuous moderate to heavy rainfall in the afternoons and early evenings. The dry phase is cool and pleasant with comparatively little or no rain.

The Southwest Monsoon Season experiences showers and thunderstorm activity between predawn to midday. However, thunderstorms usually last for less than 30 minutes. ‘Sumatra squalls’ are common during this period. These are a line of thunderstorms that develop at night over Sumatra, move to the west coast of Peninsula of Malaysia and hit Singapore during the early morning hours. Heavy rain persists for 1-2 hours, followed by cloudy conditions and light rain until afternoon. This season also experiences spells of dry weather. Sometimes Singapore is engulfed in a smoke haze – the haze is caused by smoke from forest fires in Indonesia that is carried to Singapore by the southeasterly or southwesterly winds.

Separating these two seasons is the inter-monsoon period (April-May and October-November), which experiences showers in the afternoons and early evenings. It is usually hot and dry in the months of May-July and more frequent rain spells occur during November-January.

Based on climate records, November has the highest rain days while February has the lowest. According to the National Environment Agency, Singapore receives 2342.2 mm of rain fall in an average year.

Temperature
Singapore usually witnesses a minimum of 23-26 degrees Celsius and a maximum of 31-34 degrees Celsius. Based on climate records since 1929, the lowest temperature recorded till date has been 19.4 degrees Celsius on January 31, 1934 and the highest was on March 26, 1998 at 36 degrees Celsius.

Humidity
Unfortunately, high level of humidity is something you will need to battle with in Singapore. It varies from more than 90% in the morning and falls to around 60% in the mid-afternoon, when it is not raining. It is not uncommon to find humidity levels touching a whopping 100% on rainy days. According to reports by the National Environment Agency, the average relative humidity level is 84.2%.

Source: Guide Me Singapore