Singapore, 15 September 2023 – More thundery showers are expected in the second half of September 2023, compared to the first half of the month. The prevailing Southwest Monsoon conditions will likely continue over Singapore and the surrounding region, with the low-level winds blowing mainly from the southeast or southwest.
2 In the second fortnight of September 2023, the presence of a moist air mass and slight weakening of low-level winds over Singapore and the surrounding region may bring wetter weather conditions to Singapore. Short-duration thundery showers are expected between the late morning and afternoon over parts of the island on most days. Around the middle of forecast period, regional convergence of winds may bring widespread moderate to heavy thundery showers over Singapore in the afternoon on two or three days. On the whole, we expect above average rainfall in the second half of September 2023. For the month of September, the total rainfall is expected to be above average over most parts of the island.
3 While more showers are forecast in the coming fortnight, the daily maximum temperatures are still expected to range between 32 degrees Celsius and 34 degrees Celsius on most days. On a few days, the daily maximum temperature could reach a high of slightly above 34 degrees Celsius.
4 For updates of the daily weather forecast, please visit the MSS website (www.weather.gov.sg), NEA website (www.nea.gov.sg), or download the myENV app.
REVIEW (1 – 14 September 2023)
5 Southwest Monsoon conditions prevailed over Singapore and the surrounding region in the first fortnight of September 2023 with the prevailing winds blowing mostly from the southeast or southwest.
6 Localised short-duration thundery showers fell over parts of the island in the late morning and afternoon on some days. There were several days where the weather was generally fair and occasionally windy. On 6 September 2023, large-scale convergence of winds over Singapore and the surrounding region led to the development of widespread moderate to heavy thundery showers over many parts of the island in afternoon. The daily total rainfall of 157.5 mm recorded at Lower Peirce Reservoir that day was the highest rainfall recorded for the first half of September 2023.
7 The daily maximum temperatures in the first fortnight of September 2023 were above 33 degrees Celsius on most days. The highest daily maximum temperature of 34.5 degrees Celsius was recorded at Admiralty on 7 September 2023 and 14 September 2023. On a few nights, the daily minimum temperatures over the eastern, southern and western coastal areas of the island were above 28 degrees Celsius.
8 In the first fortnight of September 2023, below average rainfall was recorded over the northeastern and southwestern parts of Singapore while above average rainfall was recorded over other parts of the island. Lower Peirce Reservoir recorded rainfall of 109 per cent above average, and Tai Seng recorded rainfall of 47 per cent below average.
CLIMATE STATION STATISTICS
Long-term Statistics for September
(Climatological reference period: 1991 – 2020)
| Average daily maximum temperature: | 31.6 °C |
| Average daily minimum temperature: | 25.2 °C |
| Average monthly temperature: | 28.0 °C |
| Average rainfall: | 124.9 mm |
| Average number of rain days: | 13 |
Historical Extremes for September
(Rainfall since 1869 and temperature since 1929)
| Highest monthly mean daily maximum temperature: | 33.0 °C (2019) |
| Lowest monthly mean daily minimum temperature: | 22.4 °C (1930) |
| Highest monthly rainfall ever recorded: | 440.4 mm (1988) |
| Lowest monthly rainfall ever recorded: | 22.8 mm (2019) |