Monthly Archives: May 2019

Singapore, 31 May 2019 – In the first fortnight of June 2019, the prevailing light and variable winds over Singapore and the surrounding region are forecast to strengthen and blow from the southeast or southwest. This signals the end of the inter-monsoon period and the start of the Southwest Monsoon season. The Southwest Monsoon season typically extends into September and is a generally drier season compared to other times of the year.

2          The weather in the first fortnight of June 2019 is forecast to be just as wet as it was in the last fortnight of May 2019. With strong day-time heating of land areas, thundery showers are expected mostly in the late morning and early afternoon on six to eight days. On two to three days in the coming fortnight, Sumatra squalls moving from the Strait of Malacca to the South China Sea could track over Singapore and bring widespread thundery showers and occasional gusty winds in the morning. The overall rainfall for the first half of June 2019 is likely to be above-normal over most parts of Singapore.

3          The warm and humid conditions in May 2019 are forecast to persist into the first fortnight of June 2019. With the setting in of the Southwest Monsoon season, more warm and humid nights can be expected; warm nights typically occur when the prevailing winds blow from the southeast and brings warm, humid air from the sea over the land. The daily temperature on most days is forecast to range between 25°C and 33°C. Night-time minimum temperatures of up to 28°C can be expected on some days.

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 May 2019)

5          Inter-monsoon conditions prevailed in Singapore and the surrounding region in May 2019. During this period, the low level prevailing winds were generally light and variable in direction, and on occasions, blew from the east or southeast.

6          In May 2019, thundery showers due to convergence of winds over Singapore and the surrounding vicinity, fell in the late morning and afternoon on most days. On several days, particularly in the second week of the month, the passage of Sumatra squalls brought widespread thundery showers to Singapore between the predawn and early morning. The thundery showers were heaviest on 16 May 2019 where the highest daily rainfall total recorded was 119.8mm at Jurong Pier. A waterspout, associated with an intense Sumatra squall, was sighted over the sea area south of Tanjong Pagar on 11 May 2019.

7          May is climatologically one of the warmest months of the year. In May 2019, the highest daily maximum temperature across the island was at least 34°C on more than half the number of days of the month. The highest daily maximum temperature of 35.0°C was recorded at Paya Lebar and Clementi on 6 and 7 May 2019 respectively. The lowest daily minimum temperature of 20.8°C was recorded at East Coast Park around predawn when a squall moved over Singapore on 8 May 2019.

8          At the climate station in Changi, May 2019’s mean monthly temperature of 29.3°C (as of 30 May 2019) is on track to tie with that in May 1997 and 2016 as the second warmest May in Singapore since temperature records started in 1929. In addition, May 2019’s mean daily minimum temperature of 26.5°C is likely to tie the record high set in May 2003 and 2016.

9          Slightly less than half of Singapore received above-average rainfall in May 2019, with most of the rain falling over the southwestern part of Singapore. The highest rainfall of 366.8 mm (78% above average) was recorded at Jurong. Rainfall was lowest over the eastern part of Singapore at Changi where 68.6 mm (56% below average) of rain was recorded.

CLIMATE STATION STATISTICS

Long-term Statistics for June
(Climatological reference period: 1981 – 2010)

Historical Extremes for June
(Rainfall since 1869 and temperature since 1929)

Singapore, 16 May 2019 – Inter-monsoon conditions that started in late March 2019 are expected to continue for the rest of May 2019. During this period, the low level winds are forecast to blow from the south or southeast.

2          In the second fortnight of May 2019, short-duration thundery showers are expected mostly between the late morning and early afternoon on six to eight days. On two to three days in particular in the first week of the coming fortnight, the occurrence of Sumatra squalls is forecast to bring widespread thundery showers accompanied by gusty winds between the predawn and morning. Overall, the rainfall for May 2019 is likely to be above-normal for many parts of Singapore.

3          The warm and humid conditions experienced during the first half of May 2019 are forecast to continue for the rest of May 2019.  The daily temperature on most days is expected to range between 26°C and 34°C, and on days with little or no rainfall, the daily maximum temperature could reach around 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 May 2019)

5          Inter-monsoon conditions prevailed over Singapore and the surrounding region in the first half of May 2019. The low level winds during the period were generally weak and variable in direction.

6          During the fortnight, the presence of the monsoon rain band near the equatorial region brought short-duration thundery showers over the island, mostly between the morning and early afternoon.  On a few of these days, the stormy weather was a result of the eastward passage of Sumatra squalls which brought widespread thunderstorms and gusty winds over Singapore between the predawn hours and morning. As a result of strong convergence of air streams in the region, two consecutive Sumatra squalls moved across Singapore on 8 May 2019 – one during the early hours and predawn, and another in the late morning. On that day, the highest daily total rainfall of 109.8 mm was recorded at Jurong West. Sumatra squalls moved across the island again on 10 and 11 May 2019. Gusty winds with speed up to 90km/h was recorded at Pasir Panjang on 10 May 2019, and a large waterspout was sighted over the sea area south of Tanjong Pagar on 11 May 2019.

7          Despite the wet weather in the first fortnight of May 2019, most days recorded maximum temperatures of 34.0°C or more. The highest daily maximum temperature of 35.0°C was recorded at Paya Lebar and Clementi on 6 and 7 May 2019 respectively. The lowest daily minimum temperature of 20.8°C was recorded at East Coast Park around predawn when the squall moved over Singapore on the 8 May 2019.

8          More than three quarters of Singapore received above average rainfall in the first fortnight of May 2019. Rainfall was lowest over the eastern part of Singapore at Changi where 40.2 mm (49% below average) of rain was recorded. The highest rainfall of 194.4 mm (89% above average) was recorded at Jurong.

CLIMATE STATION STATISTICS

Long-term Statistics for May
(Climatological reference period: 1981 – 2010)

Historical Extremes for May
(Rainfall since 1869 and temperature since 1929)