The first fortnight of February 2018 expected to be dry and warm. Short-duration thundery showers expected in the afternoon on some days.

Singapore, 1 February 2018 – The prevailing Northeast Monsoon will continue into the first half of February 2018. For the next fortnight, dry, warm and occasionally windy conditions are expected over Singapore as the region enters the dry phase of the Northeast Monsoon season. During this period, the low level winds are forecast to blow predominantly from the northeast or northwest.

2           Compared with the very wet weather experienced in January 2018, the first half of February 2018 is forecast to be relatively dry with some warm days. Short-duration thundery showers are expected in the afternoon on three to five days. In addition, a weak monsoon surge ^[1] could affect the South China Sea and the surrounding region in the early part of the month. The surge is expected to bring windy conditions with passing showers and cooler temperatures to Singapore on a few days. The rainfall for the first fortnight of February 2018 is expected to be below normal.

3           In the first half of February 2018, the daily temperatures are forecast to range between 24°C and 33°C, and could reach a high of around 34°C on a few days. Cooler temperatures can be expected with daily minimum temperatures ranging between 23°C and 24°C on windy or rainy days.

4          For updates of the daily weather forecast, please visit the MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, MSS’ Weather@SG app.

REVIEW (1 – 31 January 2018)

5          January 2018 was an eventful month for Singapore weather. The first week of January 2018 saw moderate to heavy thundery showers from three different weather systems – localised thunderstorms, Sumatra squalls and monsoon surges. In the last week of the month, hailstones and a waterspout were observed on 30 and 31 January respectively.

6          On most days of the month, thundery showers fell over Singapore in the afternoon and evening. On the morning of 8 January, a Sumatra squall brought widespread thundery showers to the island with the eastern parts of Singapore receiving the heaviest rainfall. The heavy rain resulted in flash floods in several places, and the highest total daily rainfall recorded was 131.8mm in the Paya Lebar area.

7          In the first half of January 2018, there were two occurrences of monsoon surge. The monsoon surge on 1 January was the tail-end of a 3-day monsoon surge episode that started on 30 December 2017. The second monsoon surge episode from 10 to 14 January brought five consecutive days of cool weather, with daily minimum temperatures dipping to as low as 21.2°C; this was the longest cool spell in Singapore in the last ten years. Both monsoon surge episodes brought overcast skies, windy conditions and widespread rain to Singapore and the surrounding region.

8          On 30 January 2018, intense thunderstorms brought heavy rainfall with strong winds over many areas of the island. Hailstones were observed in some parts of northern Singapore including Seletar and Yishun. The following day, another intense thunderstorm event brought strong winds and heavy rainfall to the eastern parts of Singapore. A waterspout also developed over the sea areas off the east coast of Singapore.

9          In January 2018, the daily maximum temperature ranged between 24.3°C and 34.9°C. and the daily minimum temperature was between 21.2°C and 24.1°C. The lowest temperature recorded was 21.2°C at Admiralty and Jurong West on 14 January 2018 during a monsoon surge. At the Changi climate station, the mean monthly temperature of 26.2°C for January 2018 is 0.3°C below the long-term mean for January.

10       Singapore received well above normal rainfall in January 2018. The highest rainfall of 502.4mm (119% above average) was recorded at Paya Lebar. Rainfall was lowest around the Changi area where 272.6mm (16% above average) was recorded.

[1] A monsoon surge refers to the strengthening of northeasterly winds blowing from a strong high-pressure system over the northern Asian continent toward the South China Sea, bringing periods of prolonged widespread rain and windy conditions to the surrounding region including Singapore and Peninsular Malaysia. (Further information is available at  https://www.weather.gov.sg/learn_weather_systems/).

CLIMATE STATION STATISTICS FOR FEBRUARY (Climatological reference period: 1981 – 2010)

Short-duration thundery showers expected between the afternoon and evening on most days in the next fortnight. Rainfall expected to be well-above normal in January 2018.

Singapore, 16 January 2018 – The prevailing Northeast Monsoon season is forecast to continue into the second fortnight of 2018. For the next two weeks, the low level winds over Singapore and the surrounding region are forecast to blow mostly from the northeast or northwest.

2           The second fortnight of January 2018 is not expected to be as wet as the first fortnight of the month. In the second half of the month, five to seven days of short-duration thundery showers are expected in the afternoon, and could extend into the evening on a few days. The passage of Sumatra squalls is expected to bring widespread thundery showers coupled with occasional gusty winds over Singapore between the predawn and early morning on one or two days. Overall, the rainfall for January 2018 is expected to be well above normal.

3            During the second fortnight of January 2018, the daily temperatures are forecast to range between 24°C and 32°C. On some rainy days, cooler temperatures can be expected with the daily maximum temperature ranging between 27°C and 29°C, and the daily minimum temperature ranging between 23°C and 24°C.

4          For updates of the daily weather forecast, please visit the MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, MSS’ Weather@SG app.

REVIEW (1 – 16 January 2018)

5          Northeast Monsoon conditions prevailed over Singapore and the surrounding region in the first two weeks of 2018. The low level winds during this first fortnight were predominantly from the northeast or northwest, and rain fell over the island almost every day.

6          A monsoon surge affected the South China Sea and the surrounding region over three days from 30 December 2017 to 1 January 2018. On 1 January 2018, as the surge weakened, the day was cloudy and occasionally windy, accompanied by periods of light to moderate rain. It was also cool with daily temperatures ranging from 22.7°C to 27.3°C. On several days in the first week of the year, moderate to heavy thundery showers fell in the afternoon and evening due to strong solar heating of land areas coupled with convergence of winds. On 8 January, a temporary change in the winds to blow from the southwest led to the passage of a Sumatra squall in the predawn hours and morning. The squall brought widespread thundery showers over the island, with the rainfall station at Paya Lebar recording 131.8mm of rain in a day. This was the highest total daily rainfall recorded in the first fortnight of January 2018.

7          In the second week of January 2018, another monsoon surge affected the South China Sea and the region between 10 and 14 January. The surge brought overcast skies, windy conditions and widespread rain to Singapore for five consecutive days. Over this period, the daily maximum temperature was between 24.3°C and 28.5°C while the daily minimum temperature dipped to a low of between 21.2°C and 22.4°C.

8          In the first fortnight of 2018, the daily maximum temperature ranged between 24.3°C and 33.2°C, and the daily minimum temperatures ranged between 21.2°C and 23.7°C. The lowest temperature of 21.2°C was recorded on 14 January 2018 at Admiralty and Jurong West.

9          Singapore received significantly above normal rainfall in the first fortnight of January 2018. The highest rainfall of 339.4mm (206% above average) was recorded at Paya Lebar. Rainfall was lowest around the Bukit Panjang area where 162.5mm (44% above average) was recorded.

CLIMATE STATION STATISTICS FOR JANUARY (Climatological reference period: 1981 – 2010)

2017 is the warmest year on record not influenced by an El Niño event 

Singapore, 11 January 2018 – A review of the weather and climate in 2017 was released today by the Meteorological Service Singapore (MSS). It summarises the main climatic features and notable weather events that affected Singapore and is a prelude to the comprehensive Annual Climate Assessment Report which will be released on World Meteorological Day in March 2018. The review is available on MSS’ website at https://www.weather.gov.sg (refer to Annex A for an infographic on Singapore’s Climate in 2017).

2          2017 is the warmest year on record that was not influenced by an El Niño event, indicative of the long-term temperature rise that Singapore has been experiencing due to factors such as global warming and urbanisation. After two successive record warm years in 2015 and 2016, the 2017 mean annual temperature at 27.7°C has returned to a level closer to the 1981-2010 long-term average. This is still 0.2°C warmer than the long-term average and the joint 12th warmest year on record since Singapore temperature records started in 1929.

Neutral El Niño Southern Oscillation

3          The El Niño Southern Oscillation[1] (ENSO), a naturally occurring phenomena and a major contributor to year-to-year rainfall and temperature variations over Singapore and Southeast Asia, was neutral throughout 2017 (except in November and December where it reached borderline La Niña values). Given the influence ENSO can have on temperatures, it is not surprising that following 2015’s large El Niño event which contributed to 2015 and 2016 being successive record warm years, no temperature record was broken in 2017.

4          There was a mixture of above and below normal level rainfall for the individual months in 2017, but overall the annual total rainfall was close to normal. This is more likely to be observed during a largely neutral ENSO year. The annual total rainfall of 2,045.6mm recorded was around 6 per cent below the long-term average of 2,165.9mm.

Notable weather events in 2017           

5          While 2017 was not an El Niño year, some very warm days were experienced in certain months. October 2017 in particular was warm, with temperatures soaring to above 35°C on some days. Based on the Changi climate station, the hottest day in 2017 was on 18 October 2017 with a high of 34.6°C. The normally cool months of January and December also saw warmer than usual temperatures on some days.

6          Heavy rains from intense thunderstorms caused several incidents of flash floods during the year. There were also occasional incidents of fallen trees and branches due to strong wind gusts from Sumatra squalls, and there was a high frequency of these squalls in 2017. On 18 June 2017, a waterspout associated with thunderstorm clouds was observed off Singapore’s southern coast.

7          Northeast Monsoon rains contributed to a wet February and December in 2017. The 15 rain days recorded in February 2017 was almost twice the long-term average for February, a normally dry month. The year ended on a wet note as the island experienced widespread intermittent rain from a monsoon surge and a nearby vortex in the South China Sea. High rainfall on the last two days of December 2017 raised the month’s total rainfall to 371.2mm (17 per cent above the long-term average), making December the wettest month of 2017.

[1] El Niño Southern Oscillation (ENSO) is a recurring climate pattern caused by interactions between the atmosphere and the ocean in the tropical Pacific. During El Niño, the central-eastern equatorial Pacific Ocean is warmer than usual, leading to drier and warmer conditions especially during the June to October period over Southeast Asia. During La Niña, the central-eastern equatorial Pacific is cooler than average and the atmosphere over the Southeast Asia region is typically wetter than average. El Niño or La Niña events occur on average once every three to five years.

~~ End ~~

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Annex A 

Expect more afternoon thundery showers in 1^st half of Nov’17. Showers could extend into the evening on a few days.

Singapore, 1 November 2017 – Singapore and the surrounding region are experiencing inter-monsoon conditions which are expected to prevail in November 2017. The inter-monsoon period is characterised by more rainfall and light winds that are variable in direction. Climatologically, lightning activity during the inter-monsoon period is highest during the year.

2          November is normally the second wettest month of the year after December. For the first half of November 2017, short-duration moderate to heavy thundery showers are forecast mostly in the afternoon on six or eight days. On a few of these days, the thundery showers could extend into the evening, and high lightning activity can be expected. On two or three days during the first fortnight of the month, Sumatra squalls moving eastward across Singapore towards the South China Sea could bring widespread thundery showers accompanied by gusty winds to the island between the predawn hours and early morning. Rainfall for the first fortnight of November 2017 is expected to be above normal.

3          In the first half of November 2017, the daily temperature on most days is forecast to range between 24°C and 33°C. On a few days, the daily maximum temperature could reach a high of 34°C, in particular on fine weather days when there are few clouds in the sky and winds that are light.

4          For updates of the daily weather forecast, please visit our MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, MSS’ Weather@SG app.

REVIEW (1 – 31 October 2017)

5          Southwest Monsoon conditions with low level winds blowing from the southeast or southwest prevailed over Singapore and the surrounding region in the first half of October 2017. In the third week of the month, the Southwest Monsoon eased to give way to inter-monsoon conditions where winds weakened to become light and variable in direction.

6          Except for the third week of the month, it was relatively wet in October 2017. The dry and warm conditions in the third week of October 2017 was due to stable atmospheric conditions as warm and dry air prevailed over Singapore and the surrounding region. During the month, most of the thundery showers fell in the late morning and afternoon, and on a few days, extended into the evening. The thundery showers were due to strong solar heating of land areas coupled with the convergence of winds over Singapore and the surrounding vicinity. The occurrence of Sumatra squalls on several days also brought moderate to heavy thundery showers to many parts of Singapore between midnight and early morning. The heaviest daily rainfall recorded during the period was 129.8mm around Tuas on 12 October 2017. There were 21 rain days¹ in October 2017, three days more than the long term mean for October. This ties with the highest number of rain days for October recorded in 1985 and 2003.

7          The daily temperature in October 2017 ranged between 22.6°C and 35.3°C. During the week of 16 October 2017, when conditions were warm and dry, there were five days when the daily maximum temperature was more than 34°C. At the Changi climate station, the highest daily maximum temperature recorded was 34.6°C on 18 October 2017. This ties with the highest daily maximum temperature ever recorded at our climate station in October (in 2002 and 2016). The mean monthly temperature recorded for October 2017 was 28.1°C, which is 0.5°C warmer than the long-term mean for October.

8          About half of Singapore received above normal rainfall in October 2017. The highest rainfall of 286.4mm (33% above average) was recorded around MacRitchie Reservoir. Rainfall was lowest around Admiralty where 114.8mm (46% below average) was recorded.

¹A rain day is defined as a day where 0.2mm or more of rain was recorded.

CLIMATE STATION STATISTICS FOR November (Climatological reference period: 1981 – 2010)

Dry and warm weather expected on a few days

Singapore, 16 October 2017 – The prevailing Southwest Monsoon conditions are forecast to weaken and give way to Inter-monsoon conditions in the second half of October 2017. During the second fortnight of October 2017, the low level winds are forecast to be light and variable in direction, characteristic of the inter-monsoon season which is expected to extend into November 2017.

2          Compared to the first half of October 2017 where thundery showers fell over the island on most days, the second half of October 2017 can expect a mix of dry and wet weather conditions. In the third week of October 2017, a few dry and warm weather days can be expected, and for the rest of the second fortnight, short-duration thundery showers are forecast to fall mostly in the afternoon on four to six days. On a few of these days, the thundery showers could extend into the evening. In addition, on one or two days, the eastward passage of Sumatra squalls could bring widespread thundery showers accompanied by gusty winds over Singapore between the predawn hours and early morning. Overall, the rainfall for October 2017 is expected to be slightly above normal.

3          The daily temperature on most days in the second fortnight of October 2017 is forecast to range between 24°C and 33°C. On a few days when the weather is expected to be dry and warm, or when there is strong solar heating coupled with winds that are light, the daily maximum temperature could lie between 34°C and 35°C.

4          For updates of the daily weather forecast, please visit our MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, or the MSS’ Weather@SG app.

Review: 1 – 15 October 2017

5          In the first fortnight of October 2017, Southwest Monsoon conditions prevailed over Singapore and the surrounding region, and the low level winds were blowing mostly from the southeast or southwest.

6          During the review period, Singapore experienced thundery showers mostly in the afternoon and evening due to strong solar heating of land areas coupled with convergence of winds over Singapore and the immediate surrounding vicinity. On a few days, the eastward passage of Sumatra squalls brought widespread thundery showers and gusty winds to Singapore between midnight and the early morning. In the first fortnight of October 2017, the highest daily rainfall of 129.8mm was recorded around Tuas on 12 October 2017.

7          Despite the wet weather conditions that fell over the island on most days in the first fortnight of the month, there were a few warm days where the highest temperature recorded was 35°C around the Ang Mo Kio area on 15 October 2017. The lowest daily minimum temperature recorded ranged between 22.6°C and 22.9°C.

8           In the first half of October 2017, most parts of Singapore received above-normal rainfall. The highest rainfall of 216.0mm (116% above average) was recorded around the Tai Seng area. Rainfall was lowest around Sentosa where 39.0mm (53% below average) was recorded.

CLIMATE STATION STATISTICS FOR OCTOBER (Climatological reference period: 1981 – 2010)

More thundery showers expected in the coming fortnight

Singapore, 2 October 2017 – The prevailing Southwest monsoon conditions with low level winds blowing from the southeast or southwest, will continue into the first fortnight of October 2017. However, these conditions are forecast to gradually transit to inter-monsoon conditions around the end of the fortnight, where the prevailing winds are expected to shift to become light and variable in direction.

2           With the transition to inter-monsoon conditions around mid-October 2017, an increase in the occurrence of thundery showers can be expected in the first two weeks of the month. The thundery showers which are expected on six to eight days of the first fortnight are likely to fall mostly in the late morning and afternoon, and may extend into the evening on a few days. In addition, on two or three days during this fortnight, the eastward passage of Sumatra squalls could bring widespread thundery showers accompanied by occasional gusty winds over Singapore between the predawn hours and morning. The rainfall for the first two weeks of October 2017 is expected to be above normal.

3          The daily temperature on most days in the first two weeks of October 2017 is forecast to range between 24°C and 33°C. There could be a few days where the daily maximum temperature could reach around 34°C, and on a few rainy days, the daily minimum temperature could fall to around 22°C.

4          For updates of the daily weather forecast, please visit our MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, or the MSS’ Weather@SG app.

Review: 1 – 30 September 2017

5          In September 2017, Southwest Monsoon conditions prevailed over Singapore, and the low level winds were blowing mostly from the southeast or southwest.

6          The total rainfall recorded was higher in the second half of September 2017 compared to the first half of the month. On most days of the month, Singapore experienced thundery showers in the late morning and afternoon due to strong solar heating of land areas coupled with convergence of winds over Singapore and the surrounding vicinity. On a couple of days, the thundery showers were due to the passage of Sumatra squalls that moved over Singapore in the predawn hours and early morning. The heaviest daily rainfall of 94mm was recorded on 10 September 2017 around the Sungei Kadut area.

7          There were a few warm days during the month where the daily maximum temperature reached a high of between 34.1°C and 34.9°C. The lowest daily minimum temperature recorded ranged between 21.9°C and 22.9°C on a few days where it rained for most parts of the day. At the Changi climate station, the mean monthly temperature recorded for September 2017 was 28.0°C, which is 0.4°C higher than the long-term mean temperature for September.

8          Most parts of Singapore received above-normal rainfall in September 2017. The highest rainfall of 320.2mm (68% above average) was recorded around the Jurong area. Rainfall was lowest in the eastern part of the island where 124.4mm (22% below average) was recorded around the Changi area.

CLIMATE STATION STATISTICS FOR OCTOBER (Climatological reference period: 1981 – 2010)