Windy Conditions with the Start of Northeast Monsoon

Singapore, 1 December 2021 – Inter-monsoon conditions prevailed over Singapore in November 2021, with the winds generally light and variable in direction. In the first half of December 2021, the winds around Singapore are expected to strengthen and shift to blow from the northwest or northeast. This change in monsoonal winds signal the start of the Northeast Monsoon season which is expected to extend into March 2022.

2    Climatologically, December is the wettest month of the year. In the first half of December 2021, the strengthening of the high-pressure system over the northern Asian continent is expected to bring northeast monsoonal winds over the South China Sea and equatorial Southeast Asia region, including Singapore. The monsoon rain band is forecast to lie close to the equator and bring shower activities to the surrounding region of Singapore. Singapore can expect short-duration moderate to heavy thundery showers over parts of the island in the afternoon on most days. The showers may extend into the evening on occasions. On a few days during the fortnight, Singapore may experience occasionally windy conditions. During this time, fair weather with brief periods of passing showers can be expected. The rainfall for the first fortnight of December 2021 is expected to be below-average over most parts of Singapore.

3     During the fortnight, the daily temperature is forecast to range between 24°C and 33°C on most days and may reach 34°C on some days when there is little or no cloud cover. On one or two rainy days, daily lows of around 22°C can be expected.

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


REVIEW (1 –  30 November 2021)

5     In November 2021, inter-monsoon conditions prevailed over Singapore. The low-level winds were generally light and blew mainly from the west or northwest.

6     Singapore experienced short-duration moderate to heavy afternoon thundery showers on most days in November 2021. The showers extended into the evening on a few occasions. On some days, the convergence of low-level winds in the surrounding region of Singapore led to the development of Sumatra squalls over the Strait of Malacca. The Sumatra squalls brought widespread showers with occasional gusty winds over Singapore between the early hours and morning. On 12 November 2021, the lowest minimum temperature of 22.1°C was recorded at Newton following cool and cloudy weather brought about by the passage of a Sumatra squall.

7     On 4 November 2021, strong solar heating of land areas coupled with convergence of winds in the surrounding region led to heavy rain over some parts of Singapore. A total of 118.2mm of rainfall was recorded at Sembawang that day. This was the highest daily rainfall recorded for November 2021.

8     In November 2021, there were 12 days where the daily maximum temperature was 34°C or higher. The passage of dry air mass brought relatively fair and warm weather to the surrounding region of Singapore around the end of November 2021. On 30 November 2021, the daily maximum temperature at Paya Lebar reached a high of 35.4°C.

9    In November 2021, rainfall was mostly below average over the western half of Singapore, and above average over the eastern parts of the island. The highest anomaly of 47% above average was recorded at Simei. The rainfall anomaly at Tuas was 38% below average.





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

Average daily maximum temperature: 30.5 °C
Average daily minimum temperature: 24.3 °C
Average monthly temperature: 26.8 °C
Average rainfall: 331.9 mm
Average number of rain days: 19


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

Highest monthly mean daily maximum temperature: 31.6 °C (2016, 2018)
Lowest monthly mean daily minimum temperature: 21.9 °C (1933)
Highest monthly rainfall ever recorded: 765.9 mm (2006)
Lowest monthly rainfall ever recorded: 62.5 mm (1932)