Fortnightly Weather Outlook for 16 – 30 September 2020
Singapore, 16 September 2020 – The weather for the second half of September 2020 is forecast to be less wet with a few warm days compared to the first fortnight of the month. The daily temperature is expected to range between 25°C and 33°C on most days and may reach a high of around 34°C on a few days.
2 In the coming fortnight, Southwest Monsoon conditions are expected to persist. The low-level winds are forecast to weaken but continue to blow from the southeast or southwest. The winds may shift to blow from the west on one or two days.
3 In the next two weeks, the monsoon rain band is forecast to remain over the equatorial Southeast Asia region. Short-duration moderate to heavy thundery showers can be expected over parts of the island between the late morning and afternoon on most days, and may extend into the evening on one or two days. The passage of Sumatra squalls may bring widespread thundery showers with occasional gusty winds in the morning on a few days. While rainfall in the coming fortnight is expected to be lower than that in the first fortnight of the month, the overall rainfall for September 2020 is expected to be well above-average over most parts of the island.
4 On most days in the coming fortnight, the daily temperature is forecast to range between 25°C and 33°C. A few warm days are expected with daily highs reaching around 34°C. Some nights can be relatively warm with night-time temperatures hovering around 28°C, particularly when the prevailing southeast winds blow warm and humid air from the sea toward the land.
5 For updates of the daily weather and haze situation, please visit the MSS website (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 September 2020)
6 In the first fortnight of September 2020, Southwest Monsoon conditions prevailed over the region. During this period, the low-level winds blew from the southeast or southwest.
7 The first fortnight of September 2020 was wet and occasionally windy. Thundery showers fell between the late morning and afternoon on most days, and extended into the evening on a few of these days. There were also a few days where thundery showers fell during the night and in the early morning. The widespread moderate to heavy thundery showers with occasional gusty winds on some days were due to large-scale convergence of winds over Singapore and the surrounding vicinity. The showers were heaviest on the morning of 10 September 2020. The daily total rainfall recorded that day was 129.6mm at Tuas South, which is the highest recorded for the first fortnight of September 2020.
8 The wet weather in the first fortnight of September 2020 brought cooler conditions on some days, mostly in the latter half of the fortnight. The lowest daily maximum temperature during the period was 28.3°C recorded at East Coast and at Sembawang on 5 and 13 September 2020 respectively. Both days were associated with island-wide heavy thundery showers and cloudy skies, and with minimum temperatures between 22.0°C and 23.0°C. The lowest daily minimum temperature recorded during the first fortnight of September was 21.8°C at Paya Lebar on 15 September 2020.
9 Almost all parts of the island received well above-normal rainfall in the first half of September 2020. The highest anomaly of 188% above average was recorded at Tanjong Katong. The anomaly was lowest at Admiralty at 8% below average.
CLIMATE STATION STATISTICS
Long-term Statistics for September
(Climatological reference period: 1981 – 2010)
|Average daily maximum temperature||31.4°C|
|Average daily minimum temperature||24.8 °C|
|Average monthly temperature||27.6 °C|
|Average rainfall||156.5 mm|
|Average number of rain days||13|
Historical Extremes for September
(Rainfall since 1869 and temperature since 1929)
|Highest monthly mean daily maximum temperature:||32.2 °C (1997)|
|Lowest monthly mean daily minimum temperature:||22.4 °C (1930)|
|Highest monthly rainfall ever recorded:||440.4 mm (1988)|
|Lowest monthly rainfall ever recorded:||23.7 mm (1994)|