More Thundery Showers for Rest of August 2021

Singapore, 16 August 2021 – The prevailing Southwest Monsoon conditions are forecast to persist over Singapore and the surrounding region in the second fortnight of August 2021, with the low-level winds blowing from the southeast or southwest. On a few days during the fortnight, the winds could shift to blow from the east.

2    With the monsoon rain band forecast to remain over the equatorial Southeast Asia region for the rest of the month, Singapore can expect more wet days in the coming fortnight. During the period, short-duration thundery showers are forecast over parts of the island in the afternoon on most days, and the showers could extend into the evening on a few of these days. On a few days during the fortnight, widespread moderate to heavy thundery showers are expected due to the presence of large-scale convergence of winds over Singapore and the surrounding region. In addition, the passage of Sumatra squalls could bring widespread thundery showers and gusty winds over the island on a few mornings. Overall, the total rainfall for August 2021 is forecast to be above average over most parts of the island.

3    The daily temperature on most days in the second fortnight of August 2021 is forecast to range between 24°C and 33°C. Although showers are expected on most days of the fortnight, the daily maximum temperature could still reach a high of around 34°C on a few days. Relatively warm and humid nights with minimum night-time temperatures of up to 28°C, particularly over the eastern and southern coastal areas of the island can be expected on a few days when prevailing southeast winds bring warm, humid air from the surrounding seas.

4      For updates of the daily weather forecast, please visit our MSS website (, NEA website (, or download the myENV app.


REVIEW (1 – 15 August 2021)

5      In the first half of August 2021, Southwest Monsoon conditions persisted over the region, and the low-level winds were blowing from the southeast or southwest.

6      Compared to the second fortnight of July 2021, the first fortnight August 2021 was wetter due to a return of showers in the region. During the first fortnight of the month, thundery showers fell mostly in the afternoon and there were a few days where Sumatra squalls brought thundery showers in the morning. On 1 August 2021 in particular, a Sumatra squall brought heavy thundery showers with gusty winds over many parts of Singapore in the morning. The daily total rainfall of 97.8mm recorded at Choa Chu Kang that day was the highest daily rainfall for the first half of August 2021.

7      The return of showers in the first fortnight of August 2021 brought some respite to the warm weather in the second half of July 2021. On most days in the first two weeks of August 2021, the highest daily maximum temperature was below 34°C. The lowest daily minimum temperature recorded during the period was 21.9°C at Pulau Ubin on 3 August 2021.

8      There were still a few warm days in the first fortnight of August 2021. The highest daily maximum temperature of 34.9°C was recorded at Marina Barrage on 3 August 2021. There were also a few warm nights, particularly over the southern and south-eastern parts of the island where the night-time minimum temperature was around 28.0°C.

9      Slightly more than half of the island recorded above average rainfall in the first half of August 2021, with most of the rain falling in the western half of Singapore. The highest anomaly of 128% above average was recorded at Jurong West. The anomaly was lowest at Yio Chu Kang at 37% below average.





Long-term Statistics for August
(Climatological reference period: 1991 – 2020)

Average daily maximum temperature 31.4 °C
Average daily minimum temperature 25.3 °C
Average monthly temperature 28.1 °C
Average rainfall 146.9 mm
Average number of rain days 14


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

Highest monthly mean daily maximum temperature: 32.7 °C (2019)
Lowest monthly mean daily minimum temperature: 23.0 °C (1962)
Highest monthly rainfall ever recorded: 526.8 mm (1878)
Lowest monthly rainfall ever recorded: 11.8 mm (2019)