SINGAPORE: Singapore experienced its wettest August in more than 40 years, said the Met Service on Wednesday (Sep 1), adding that the first half of September is likely to be less wet.
"Based on the rainfall averaged over long-term stations islandwide, August 2021 is the wettest August since 1980, with a monthly total rainfall of 426.2mm," said the Met Service.
"This has surpassed the record highest August rainfall of 346.6mm set in August 1996."
At the Changi climate station, a total of 24 rain days was recorded last month, which is well above the long-term average of 14 days for August, said the Met Service.
It noted that on Aug 24, "a few spells of widespread moderate to heavy thundery showers fell over the island in the pre-dawn hours and morning, followed by light to moderate rain in the afternoon".
That was the day flash floods were reported in parts of Singapore, including the Upper Bukit Timah area.
The highest daily total rainfall recorded on Aug 24 was 247.2mm at Mandai.
It surpasses the previous high for daily total rainfall in August, which was 181.8mm recorded at Changi on Aug 22, 1983.
The Met Service said the wet weather can be attributed to the weather phenomenon Indian Ocean Dipole - the convergence of surrounding winds and the passage of a wet phase of rain clouds moving eastward over the equatorial region.
Because of the rainy weather, the daily maximum temperature in August was kept below 34 degrees Celsius on most days. The lowest daily minimum temperature of 21.3 degrees Celsius was recorded at Newton on Aug 24.
"There were a few warm days mainly in the first half of August 2021, and the highest daily maximum temperature recorded in August 2021 was 34.9 degrees Celsius at Marina Barrage on Aug 3," the Met Service added.
OUTLOOK FOR SEPTEMBER
In its fortnightly outlook, the Met Service said the weather in the first half of September is expected to be less wet with a few warm days compared to the previous two weeks.
On most days, short thundery showers are forecast between the morning and early afternoon over some parts of Singapore.
There may be widespread thundery showers with occasional gusty winds on some days, between the early and pre-dawn hours, due to Sumatra squalls from the Strait of Malacca, the Met Service said.
"On one or two days, widespread moderate to heavy thundery showers can be expected when prevailing winds in the region converge over Singapore and the surrounding region," it added.
The total rainfall for the first half of September is expected to be above average over most parts of the island.
The daily temperature is expected to range between 24 degrees Celsius and 33 degrees Celsius.
But in the later half of the fortnight, this could hit a high of about 34 degrees Celsius on a few days. On one or two rainy days, the mercury could dip to around 22 degrees Celsius.
On some nights, warm and humid conditions can be expected when prevailing winds from the southeast or south blow warm and humid air from the sea, said the Met Service.
The minimum night-time temperatures may reach around 28 degrees Celsius, particularly over the southeastern parts of the island.
Editor's note: An earlier version of this story said that the previous record August rainfall was 296.3mm, set in 1996. NEA has since corrected this to 346.6mm.