SINGAPORE - Remember to have your umbrellas and raincoats in hand because heavy downpours are expected from March 19 to 21 as the year’s third monsoon surge arrives.
This could offer some respite from the recent hotter weather as temperatures could dip to around 22 deg C, amid periods of moderate to heavy showers over Singapore, said the Meteorological Service Singapore (MSS) in its fortnightly weather outlook on March 17.
However, this upcoming surge event – which typically brings widespread and prolonged rain – is uncommon as monsoon surges tend to occur during the earlier phase of the North-east Monsoon season, between December and January. Singapore is currently in the end phase of the monsoon season, which lasts till March or so.
Overall, the rainfall for the second half of March 2025 is expected to be above average over most parts of the island, said MSS, which is under the National Environment Agency.
A monsoon surge refers to bursts of cold air from the north-east, such as Central Asia, which flow over the South China Sea before bringing widespread rainfall, strong winds and cooler weather to Singapore. The Republic experiences two to four monsoon surges each year, on average.
The last two events this year were in January, from Jan 10 to 13 and Jan 17 to 19. During the first monsoon surge, a total of 255.2mm of rainfall was recorded in Changi between Jan 10 and 11, which exceeded the country’s average monthly rainfall for the month.
The rainfall event on Jan 10 led to a nearly three-hour flood at a side road bend of Jalan Seaview in Mountbatten as the prolonged rain coincided with a high tide of 2.8m.
Businesses in Chinese New Year bazaars and at the Chinatown Street Market were affected by the Jan 11 and 12 downpours, with some stalls reporting that their revenue dropped by more than 60 per cent.
Now, Ramadan bazaars islandwide are in full swing, with the two main ones in Geylang Serai and Kampong Gelam.
Beyond March 21, daily temperatures may range between 24 deg C and 34 deg C on most days, said MSS.
The last time Singapore had rare, late wet monsoon surges was between end-February and early March 2023.
That year, the first episode between Feb 28 and March 1 brought widespread and continuous thundery showers over Singapore and the surrounding region with all weather stations across the island recording more than 100mm of rainfall, stated the Republic’s 2023 annual climate assessment report.
A couple days later on March 3 and 4 that year, another monsoon surge descended, bringing cool weather that week. The highest temperature on both days was 26.1 deg C at East Coast Parkway.
The mercury in Newton dipped to 21.1 deg C during the monsoon surge on 1 March 2023, and that was the lowest temperature recorded in 2023.
Shabana Begum is a correspondent, with a focus on environment and science, at The Straits Times.
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