Fortnightly Weather Outlook for 1 – 15 August 2019
Singapore, 1 August 2019 – The prevailing Southwest Monsoon conditions in the region are forecast to persist in the first fortnight of August 2019 and last till October 2019. During the period, the low level winds are expected to blow from the southeast or south.
2 During the fortnight, the monsoon rain band is forecast to maintain its position over the northern Southeast Asia region. Furthermore, with the occasional intrusion of dry air from high pressure systems in the southern hemisphere, the weather during the fortnight is forecast to be drier than that in the second half of July 2019. The prevailing winds extending from these high pressure systems are expected to strengthen around the equatorial region. This can bring occasional breezy conditions on some days to Singapore and the surrounding vicinity.
3 Despite the drier conditions in the coming fortnight, localised short-duration thundery showers can still be expected on four or five days in the late morning and early afternoon. In addition, Sumatra squalls are forecast to bring thundery showers and gusty winds in the morning on one or two days. The rainfall in the coming fortnight is likely to be well-below normal.
4 The first fortnight of August 2019 is expected to be as warm as the last fortnight of July 2019. The daily temperature over Singapore is forecast to range between 26°C and 33°C, and could exceed 34°C on some days. In addition, on some nights, warm and humid conditions with night-time minimum temperatures of around 28°C can be expected when prevailing winds blowing from the southeast bring in warm air from the surrounding seas.
5 The surrounding region is also expected to experience dry weather in the coming weeks. Hotspots with smoke plumes have been observed in central Sumatra and southern Kalimantan in recent days. Depending on the direction of the prevailing winds and location of the fires, Singapore may experience occasional haze in the first fortnight of August 2019.
REVIEW (1 – 31 July 2019)
7 In July 2019, Southwest Monsoon conditions continued to persist with the low level winds blowing from the southeast or southwest.
8 In the first half of July 2019, short-duration thundery showers fell in the late morning and afternoon on most days due to strong solar heating of land areas and convergence of winds in the surrounding vicinity. The highest daily total rainfall for July 2019 was 51.6mm recorded at Mandai on 8 July 2019. The second half of July 2019 was mostly dry and warm over Singapore and the surrounding region, partly due to a mass of dry air blowing from the southern hemisphere toward the equatorial region. At the Changi climate station, the total rainfall recorded for July 2019 was 12.2mm. This makes July 2019 the driest July in Singapore since rainfall records began in 1869. The previous record was 18.6mm set in July 1997.
9 July 2019 was also a warm month. The daily maximum temperature in July 2019 ranged between 28.7°C and 34.5°C. There were also a few warm nights where the night-time temperature was around 28°C mostly over the southern and eastern parts of the island. At the climate station in Changi, the monthly average temperature for July 2019 was 29.0°C. This ranks July 2019 as the second warmest July on record since temperature records began in 1929, after July 2015 with an average temperature of 29.1°C. The average minimum temperature for July 2019 was 26.9°C, surpassing the July record high temperature of 26.7°C in 2015.
10 Well-below-average rainfall was recorded across the island in July 2019. The lowest anomaly of 92% below-average was recorded at Changi.
CLIMATE STATION STATISTICS
Long-term Statistics for August
(Climatological reference period: 1981 – 2010)
|Average daily maximum temperature||31.4 °C|
|Average daily minimum temperature||25.0 °C|
|Average monthly temperature||27.9 °C|
|Average rainfall||148.9 mm|
|Average number of rain days||14|
Historical Extremes for August
(Rainfall since 1869 and temperature since 1929)
|Highest monthly mean daily maximum temperature:||32.6 °C (1997)|
|Lowest monthly mean daily minimum temperature:||23.0 °C (1962)|
|Highest monthly rainfall ever recorded:||526.8 mm (1878)|
|Lowest monthly rainfall ever recorded:||18.0 mm (1888)|