Singapore, 16 December 2021 – The Northeast Monsoon conditions which prevailed since the start of December 2021 are expected to continue in the second half of the month, with winds blowing mainly from the northwest or northeast.
2 The month of December is usually associated with wet weather and occasional windy conditions. However, the Northeast Monsoon conditions in the coming fortnight are forecast to be generally weak with fewer windy days as compared to the first half of the month. While the rest of December 2021 will likely be less rainy than usual, short-duration afternoon thundery showers can still be expected on most days. On some of these days, the showers may extend into the evening. In the first few days of the fortnight, the passage of Sumatra squalls may bring widespread rain, with occasional gusty winds, between the pre-dawn hours and morning. Overall, the rainfall for December 2021 is expected to be well below-average across the island.
3 For the next two weeks, the daily temperature is expected to range between 24°C and 33°C on most days, with highs of 34°C on a few days. The temperature may drop to 22 – 23 °C on a few rainy days.
REVIEW (1 – 15 December 2021)
5 In the first half of December 2021, moderate to strong Northeast Monsoon conditions prevailed over Singapore and the surrounding region, and the low-level winds blew mainly from the northwest or northeast.
6 For the first fortnight of December 2021, the Northeast Monsoon brought relatively windy conditions with passing showers to Singapore and the surrounding region on most days, particularly in the second week of December 2021. The strongest wind gust of 68.3 km/hr was recorded at Admiralty on 13 December 2021. On 10 and 11 December 2021, the convergence of low-level winds in the surrounding region of Singapore triggered several spells of widespread rain across the island in the afternoon and evening. The highest daily total rainfall of 78.8mm was recorded at West Coast on 10 December 2021.
7 On 1 December 2021, a daily maximum temperature of 34.8°C was recorded at Tengah. This was the highest daily maximum temperature in the first half of December 2021. On the same day, the temperature at the Changi climate station reached a record high of 33.9 °C, surpassing the previous climate station record of 33.8 °C for the month of December. On 2 December 2021, the passage of a Sumatra squall brought rainy weather and cloudy skies to Singapore, and the minimum temperature at Jurong West dropped to a low of 22.1°C.
8 In the first half of December 2021, rainfall was well below-average across the whole island. The rainfall anomaly at MacRitchie Reservoir was 81% below average.
CLIMATE STATION STATISTICS
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)|