Rainfall for the second half of March 2025 is expected to be above average over most parts of the island. -- ST PHOTO: SHINTARO TAY
SINGAPORE (The Straits Times/ANN): 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.
Beyond March 21, daily temperatures may range between 24 deg C and 34 deg C on most days, it added.
For the rest of the fortnight, short-duration thundery showers are forecast in the afternoon on most days. Overall, 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.
In the first half of March 2025, the daily highest temperatures were between 28.2 deg C and 35.1 deg C, said MSS in its fortnightly report.
There were six days when the daily maximum temperature reached 34 deg C or more. The mercury hit 35.1 deg C in Newton on March 4.
In the past two weeks, thundery showers have fallen over parts of the island in the afternoon on most days, but overall, most parts of Singapore recorded below-average rainfall.
The 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.
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.
Intense rainfall may overwhelm drains and canals temporarily, causing flash floods, cautioned national water agency PUB in a Facebook post on March 17.
PUB urged commuters to adjust travel plans between March 19 and 21, if needed, and check for flood risks and plan travel routes accordingly. PUB Flood Alerts on the Telegram messaging app gives a heads-up on areas to avoid if there is a flood risk, with updates on flash flood incidents.
The last two monsoon surge events in 2025 were from Jan 10 to 13, and from Jan 17 to 19. During the first event, 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 at Chinese New Year bazaars and 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 Glam.
The last time that 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, according to the Republic’s 2023 annual climate assessment report.
A couple of 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 March 1, 2023, and that was the lowest temperature recorded in 2023. - The Straits Times/ANN
