Fortnightly Weather Outlook for 1 – 15 December 2020
Singapore, 1 December 2020 – The prevailing Northeast Monsoon conditions in the region are expected to persist over the next few months. During the period, the low-level winds are forecast to blow from the northwest or northeast.
2 Climatologically, December is the wettest month of the year. In the first fortnight of December 2020, with the monsoon rain band forecast to lie close to the equator, more showers can be expected over Singapore and the surrounding region. Short-duration moderate to heavy thundery showers are forecast over parts of the island in the afternoon on most days. These showers may extend into the evening on a few occasions. On a few days, the thundery showers could be intense and widespread due to large-scale convergence of winds over Singapore and the surrounding vicinity. A strengthening of the north-easterly winds can be expected in the latter half of the fortnight. This is forecast to bring occasionally windy conditions on some days. The rainfall for the first fortnight of December 2020 is expected to be near-normal over most parts of Singapore.
3 In the coming fortnight, the daily temperature is forecast to range between 24°C and 33°C on most days, and may reach 34°C on one or two days. On a few rainy days, daily lows of around 22°C can be expected.
REVIEW (1 – 30 November 2020)
5 Inter-monsoon conditions prevailed for most parts of November 2020 where the prevailing winds were generally light and variable in direction. A change in low-level winds to blow from the northwest or northeast in the last week of November 2020 signalled the cessation of the inter-monsoon period and the start of the Northeast Monsoon season.
6 Singapore experienced generally wet conditions in November 2020. The thundery showers fell in the afternoon on most days and on a few occasions extended into the night. On a few of these days, the thundery showers were intense and widespread. The wet weather can be attributed to strong solar heating of land areas coupled with large scale convergence of winds over Singapore and the surrounding vicinity. On 2 November 2020, intense thundery showers fell over many parts of the island. The daily total rainfall recorded that day was 134.2mm at Paya Lebar. This was the highest total rainfall in a day for November 2020.
7 While the prevailing La Niña conditions may have an influence on the rainfall in November 2020, other sources of variability such as monsoonal and local wind conditions play a more dominant role in modulating the weather conditions on a day-to-day basis.
8 There were a few warm days in November 2020, mainly in the first fortnight of the month. The highest daily maximum temperature of 34.9°C was recorded at Clementi and Paya Lebar on 5 and 12 November 2020 respectively. In the second fortnight of November 2020, rainy weather and cloudy skies brought cooler temperatures. The lowest daily minimum temperature of 22.3°C was recorded at Pulau Ubin on 28 November 2020. At the climate station in Changi, November 2020 recorded a monthly mean temperature of 27.2°C, making November 2020 the second coolest November in the past 10 years.
9 In November 2020, rainfall was above average over most parts of the island. The highest anomaly of 78% above average was recorded at Paya Lebar. The rainfall anomaly was lowest at Queenstown at 19% below average.
CLIMATE STATION STATISTICS
Long-term Statistics for December
(Climatological reference period: 1981 – 2010)
|Average daily maximum temperature||30.2 °C|
|Average daily minimum temperature||24 °C|
|Average monthly temperature||26.4 °C|
|Average rainfall||318.6 mm|
|Average number of rain days||18|
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)|