Monthly Archives: October 2020

Singapore, 16 October 2020 – In the second fortnight of October 2020, the monsoon rain band is forecast to lie over the northern Southeast Asia region. During the period, Singapore can expect dry and warm conditions, with daily highs of around 34°C on most days.

2        The prevailing Southwest Monsoon conditions with low-level winds blowing from the southeast or southwest are expected to persist in the second half of October 2020. With low-pressure systems expected to develop over the northern South China Sea, the low-level winds over Singapore and the surrounding vicinity are forecast to strengthen and blow from the west on some days.

3         During this fortnight, it is forecast to be dry and warm. However, localised short-duration moderate to heavy thundery showers can still be expected on some days over parts of the island between the late morning and afternoon. In addition, Sumatra squalls are forecast to bring thundery showers and gusty winds on some days between the predawn hours and morning. Overall, the rainfall for October 2020 is forecast to be below normal over most parts of Singapore.

4         Warm conditions are expected on most days for the rest of the month, and the daily temperature is forecast to range between 25°C and 34°C. The daily maximum temperature could reach close to 35°C on a few days, particularly when there are few clouds in the sky.

5         For updates of the daily weather and haze situation, please visit the MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, MSS’ Weather@SG app, and the haze microsite (www.haze.gov.sg).

REVIEW (1 – 15 October 2020)

6      In the first half of October 2020, Southwest Monsoon conditions prevailed over Singapore and the surrounding region. During the period, the low-level winds blew from the southeast or southwest. There were some days when the winds over Singapore and the surrounding region strengthened to blow from the west due to the presence of tropical storms over the South China Sea and the northwestern Pacific Ocean.

7     The influence of these tropical storms resulted in large-scale wind convergence over Singapore and the surrounding vicinity. Widespread moderate to heavy thundery showers fell over the island on several days, mostly between the night and predawn hours. The showers were due to the passage of Sumatra squalls from the Strait of Malacca over Singapore. The showers were heaviest on 2 October 2020, and the daily total rainfall recorded that day was 108.2mm at Tuas. This was the highest rainfall recorded in a day for the first fortnight of October 2020.

8      During the fortnight, the occurrence of these Sumatra squalls brought cloudy and cool conditions on most days. The daily maximum temperature across the island was below 34°C on all days except on 5 October 2020. The maximum temperature recorded that day was 34.8°C at Pulau Ubin. The lowest daily minimum temperature recorded in the fortnight was 22.6°C at Clementi on 3 October 2020.

9     In the first half of October 2020, rainfall was above average over the western part of the island, while for the rest of the island, rainfall was below average. Choa Chu Kang recorded the highest rainfall anomaly of 87% above average, while MacRitchie in the central part of Singapore recorded the highest rainfall anomaly of 57% below average.

CLIMATE STATION STATISTICS

Long-term Statistics for October
(Climatological reference period: 1981 – 2010)

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

Singapore, 1 October 2020 – According to the Meteorological Service Singapore, more thundery showers are expected in the first fortnight of October 2020. During the period, the daily temperature is forecast to range between 24°C and 33°C on most days, with lows of around 22°C on a few days.

2        The prevailing Southwest Monsoon conditions are expected to persist in the two weeks ahead. During the period, the low-level winds are forecast to continue blowing from the southeast or southwest and may strengthen to blow from the southwest or west in the latter part of the fortnight under the influence of developing low pressure systems over the South China Sea.

3          In the first fortnight of October 2020, with the monsoon rain band forecast to lie closer to the equatorial Southeast Asia region, more rain can be expected over Singapore. During the period, short-duration moderate to heavy thundery showers are forecast between the late morning and afternoon on some days due to strong solar heating of land areas. On a few of these days, the showers could continue into the evening over some parts of the island. In the latter half of the fortnight, strong convergence of winds in the surrounding vicinity and the passage of Sumatra squalls are expected to bring widespread moderate to heavy thundery showers with occasional gusty winds between the predawn hours and morning on several days. In addition, thundery showers can be expected on a few nights. The rainfall for the first fortnight of October 2020 is forecast to be above average over most parts of the island.

4          For the next two weeks, the daily temperature is forecast to range between 24°C and 33°C on most days. On one or two days, the daily maximum temperature could rise to around 34°C. On a few rainy days, daily lows of around 22°C can be expected.

5         For updates of the daily weather and haze situation, please visit the MSS website (https://www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app, MSS’ Weather@SG app, and the haze microsite (www.haze.gov.sg).

REVIEW (1 – 30 September 2020)

6      Southwest Monsoon conditions prevailed over the region in September 2020. The low-level winds blew from the southeast or southwest on most days, and from the east or west on a few days.

7      September 2020 was relatively wet and occasionally windy. Thundery showers fell over the island in the late morning and afternoon on most days, and on a few days, the rain continued into the evening. Under the influence of large-scale convergence of winds over Singapore and the surrounding vicinity, moderate to heavy thundery showers fell over the island on several nights. On the morning of 10 September 2020, heavy thundery showers fell over the western part of Singapore. The total daily rainfall recorded that day was 129.6mm at Tuas South, which is the highest total rainfall recorded in a day for September 2020.

8       The wet and cloudy conditions brought cooler temperatures on some days around mid-September 2020. The lowest daily maximum temperature in September 2020 was 28.3°C recorded at East Coast and Sembawang on 5 and 13 September 2020 respectively. Both days were associated with island-wide thundery showers that fell throughout most parts of the day. The lowest daily minimum temperature in September 2020 was 20.9°C recorded at Newton on 16 September 2020, associated with a Sumatra squall that brought heavy thundery showers and gusty winds over the island in the early hours of the morning. The last time that the temperature dipped below 21.0 °C was on 8 May 2019 when a minimum temperature of 20.8 °C was recorded.

9       There were a few warm days in September 2020 with daily maximum temperatures reaching around 34.0°C. On 22 September 2020, with relatively clear skies and presence of high-level clouds, a halo formed by the refraction of light through ice crystals in the high clouds was spotted encircling the sun around noon.

10      With a monthly total rainfall of 150.2mm recorded at the Changi climate station, September 2020 is the second wettest September in the last 10 years after September 2013 (257mm). September 2020 is the coolest September in the last 10 years. It  ties with September 2013, with a monthly mean temperature of 27.5°C, 0.1°C lower than the long term September average.

11       Almost all parts of the island received well above-normal rainfall in September 2020. The highest anomaly of 121% above average was recorded at Jurong West. The anomaly was lowest at Changi at 1% below average.

CLIMATE STATION STATISTICS

Long-term Statistics for October
(Climatological reference period: 1981 – 2010)

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