Monthly Archives: December 2021

December 31, 2021

Wet And Cool Start To The New Year

Singapore, 31 December 2021 – The prevailing Northeast Monsoon conditions in the region are forecast to persist into January 2022, with low-level winds blowing from the northwest or northeast. At the start of the new year, a high-pressure system over the northern Asian continent is expected to strengthen and bring wetter and cooler conditions to the region.

2    The strengthening of the high-pressure system is expected to bring a surge of strong north-easterly winds (or monsoon surge ) over the South China Sea. The surge will last for a few days and will likely bring cooler conditions with occasional spells of moderate to heavy thundery showers over Singapore and the surrounding vicinity. Thereafter, localised thundery showers are forecast in the afternoon. The rainy weather is likely to ease in the second week of the fortnight. Localised short-duration thundery showers can still be expected in the afternoon on several days, and warm and occasionally windy conditions with passing showers on a few days. Overall, the rainfall for the first half of January 2022 is expected to be slightly above average over most parts of the island.

3    The rainy weather in early January 2022 is likely to result in lower daily temperatures of between 23 °C and 31 °C on a few days. For the rest of the fortnight, the daily temperatures are forecast to range between 24°C and 33°C. The daily maximum temperature may still reach a high of up to 34oC on a few days.

4      For updates of the daily weather forecast, please visit our MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app.

 

REVIEW (1 – 30 December 2021)

5    In December 2021, Northeast Monsoon conditions prevailed over Singapore and the surrounding region. During this period, the low-level winds blew from the northwest or northeast.

6    While December is climatologically a wetter month than November, December 2021 was drier compared to November 2021. The Northeast Monsoon brought relatively windy conditions with passing showers to Singapore and the surrounding region on most days in the first half of the month. Short-duration thundery showers fell over parts of the island in the afternoon on most days in the second half of December 2021. On a few days, large-scale convergence of winds over Singapore and the surrounding vicinity brought widespread moderate to heavy thundery showers. On the night of 18 December 2021, intense thundery showers fell over many parts of the island. The daily total rainfall recorded that day was 82.6 mm around the Pulau Ubin area. This was the highest total rainfall in a day for December 2021.

7    The daily temperature in December 2021 ranged between 22.1oC and 34.8oC. The highest daily maximum temperature of 34.8 °C was recorded on 1 December at Tengah. On 2 December 2021, the passage of a Sumatra squall brought rainy weather and cloudy skies to Singapore, and the minimum temperature at Jurong dropped to a low of 22.1°C.

8    At the Changi climate station, the daily maximum temperature of 33.9°C recorded on 1 December 2021 was the highest daily maximum temperature ever recorded at our climate station in December. The mean monthly temperature of 27.7°C (as of 30 Dec 2021) was 0.9°C warmer than the long-term December mean temperature.

9 Singapore received below-average rainfall in December 2021. The highest anomaly of 71% below average was recorded at Seletar. The lowest anomaly of 7% below average was at Jurong Pier.

 

CLIMATE STATION STATISTICS

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

Average daily maximum temperature: 30.6 °C
Average daily minimum temperature: 24.3 °C
Average monthly temperature: 26.8 °C
Average rainfall: 221.6 mm
Average number of rain days: 13

 

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

Highest monthly mean daily maximum temperature: 31.8 °C (2016, 2018)
Lowest monthly mean daily minimum temperature: 21.6 °C (1933)
Highest monthly rainfall ever recorded: 818.6 mm (2006)
Lowest monthly rainfall ever recorded: 15.4 mm (1932)

 

December 16, 2021

Fewer Windy Days for the rest of December 2021

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.

4    For updates of the daily weather forecast, please visit our MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app.

 

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)

 

December 1, 2021

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 (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), 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.

 

 

 

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)