Southwest Monsoon to bring drier and warmer conditions. Localized and short-duration thundery showers forecast on three to five days in late morning and early afternoon. Widespread showers with gusty winds on one to two days in predawn hours and morning.
Singapore, 1 June 2018 – The Southwest Monsoon is expected to set in during the first fortnight of June 2018, with the prevailing winds strengthening and blowing predominantly from the southeast or southwest. The Southwest Monsoon season typically last till September and is characterised by relatively drier and warmer weather conditions.
2 During the coming fortnight, drier conditions can be expected compared to the previous fortnight in May 2018. Localized short duration thundery showers are forecast in the late morning and early afternoon on three to five days due to strong heating of the land areas. In addition, widespread showers with gusty winds are likely in the predawn hours and morning on one to two days. Rainfall for the first fortnight of June 2018 is likely to be below normal.
3 With lesser rainfall, generally warmer temperatures can be expected. During this period, the daily temperature is expected to range between 25°C and 34°C on most days, with the possibility of reaching 35°C on a few days.
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, MSS’ Weather@SG app.
REVIEW (1 – 31 May 2018)
5 Inter-monsoon conditions persisted in Singapore in May 2018. The low level prevailing winds were generally light and variable in direction, occasionally blowing from the east or southeast.
6 During the month, thundery showers affected Singapore in the late morning and afternoon on most days, and extended into the evening on some days. On 13 May 2018, widespread moderate to heavy thundery showers affected Singapore between the early hours and mid-day due to strong convergence of winds over Singapore. During the event, heavy rain fell over western parts of Singapore between 7am and 11am, with the highest daily total rainfall of 121.6mm recorded over the Choa Chu Kang area. The second half of the month was generally wetter than the first half.
7 For the month of May 2018, the daily maximum temperature ranged between 30.8°C and 35.4°C, and the daily minimum temperature ranged between 22.4°C and 27.0°C. There were up to 5 days with temperatures greater than 35.0°C recorded on the 3, 4, 12, 24 and 25 May 2018 over the northern, southern and western parts of Singapore. The night-time temperatures were also warm on some days, especially during the second week of the month when the night-time temperature stayed above 27.0°C.
8 About three quarters of Singapore received above-normal rainfall in May 2018. The lowest rainfall of 118.0 mm (36% below average) was recorded at Sentosa. Rainfall was highest around Paya Lebar where 343.8 mm (79% above average) was recorded.
CLIMATE STATION STATISTICS FOR JUNE (Climatological reference period: 1981 – 2010)
| Mean daily maximum temperature | 32 °C |
| Mean daily minimum temperature | 25.4 °C |
| Mean monthly temperature | 28.3 °C |
| Mean rainfall for the month | 130.7 mm |
| Mean number of rain days | 12 |
| Highest monthly mean daily maximum temperature | 33.2 °C (1991) |
| Lowest monthly mean daily minimum temperature | 24.4 °C (1989) |
| Highest monthly rainfall | 265.8 mm (1996) |
| Lowest monthly rainfall | 21.8 mm (2009) |