2009-2018 is the warmest decade on record
Singapore, 15 January 2019 – 2018 saw a continuation of above-average temperatures over Singapore, with the year recording a mean annual temperature of 27.9°C. This is 0.4°C higher than the 1981-2010[1] long-term average, and 0.2°C warmer than 2017’s mean annual temperature of 27.7°C, making 2018 the joint eighth warmest year on record. Above-average temperatures were recorded in all months in 2018 with the exception of January, when Singapore experienced an extended cool spell on 10 – 14 January.
2 Notably, December 2018 was the second warmest December in Singapore with a monthly mean temperature of 27.6°C, behind December 2015 (27.7°C). The second half of the month was particularly warm; on 28 and 30 December the Changi climate station recorded a daily maximum temperature of 33.8°C, tying the record set on 2 December 1948 for a December day. Temperature records for Singapore started in 1929.
3 Singapore’s top ten warmest years have all occurred in the past 25 years, and eight of them were recorded in this century. Significantly, the last decade from 2009 to 2018 marks the warmest decade on record in Singapore with mean temperature of 27.89°C, surpassing the previous record (1997 to 2006) by 0.02°C. These are signs of the long term warming trend in Singapore.
4 These findings are detailed in a review of Singapore’s weather and climate in 2018 released today by the Meteorological Service Singapore (MSS). The review summarises the main climatic features and notable weather events that affected Singapore in 2018 and is a prelude to the comprehensive Annual Climate Assessment Report which will be released in conjunction with World Meteorological Day in March 2019. The review is available on the MSS website at www.weather.gov.sg (please refer to Annex A for an infographic on Singapore’s Climate in 2018).
El Niño Southern Oscillation
5 2018 was largely an El Niño Southern Oscillation (ENSO) neutral year with no significant influence on Singapore’s climate. Weak La Niña conditions prevailed in the first quarter of 2018 and there were signs of a weak El Niño developing towards the end of 2018.
6 The 2018 annual total rainfall recorded in most parts of the island was close-to-average. At the Changi climate station, however, well below average monthly rainfall was recorded in some months, in particular from February to April. This contributed to an annual total rainfall of 1,708 mm, 21 per cent below the 1981-2010 long-term average.
Notable weather events in 2018
7 January 2018 was an eventful month for Singapore’s weather. A monsoon surge[2] from 10 to 14 January brought five consecutive days of cool weather across the Island, with the daily minimum temperature dipping to 21.2°C on 14 January. This was the longest cool spell Singapore has experienced in at least two decades. On 30 January, intense thunderstorms brought rain and hailstones over the northern parts of the island. This is relatively rare in the tropics where hailstones usually melt before reaching the ground. On 31 January, a waterspout[3] associated with an intense thunderstorm developed over the sea areas off the east coast of the island. Strong wind gusts from the waterspout blew sail boats on the beach a few meters inland.
8 During the year, heavy rains and strong wind gusts from intense thunderstorms caused several incidents of flash floods, fallen trees and damage to property. In particular, on 30 March, strong wind gusts from an intense thunderstorm caused substantial damage to chicken farms in the Lim Chu Kang area. The wind gust of 133.3 km/h recorded at the nearby Tengah station on that day was the strongest wind gust recorded since 2010.
[1] A “normal climate”, usually termed “Climate Normals”, is the 30-year average of climatological variables, such as temperature and rainfall, updated every 10 years. The current Climate Normals are defined by the baseline period from 1981-2010. This average is the basis of comparison for recent climate conditions, such as whether the mean temperature for a recent month or year is above or below normal.
[2] A monsoon surge refers to the strengthening of north-easterly winds blowing from a strong high-pressure system over the northern Asian continent toward the South China Sea, bringing periods of prolonged and widespread rain and windy conditions to the surrounding region including Singapore and Peninsular Malaysia.
[3] A waterspout is a rotating column of winds associated with intense thunderstorms over the sea. Typically, waterspouts have strong wind gusts of 40 – 80km/h. They lose their energy quickly upon nearing the coast, and are usually short-lived.