Singapore, 16 July 2021 – The weather in the second fortnight of July 2021 is forecast to be less wet compared to the first fortnight of the month. During the coming fortnight, the prevailing Southwest Monsoon conditions are expected to persist and the low-level winds over Singapore are forecast to continue blowing from the southeast or southwest.
2 In the second fortnight of July 2021, the monsoon rain band is forecast to lie over the northern Southeast Asia region. This is expected to bring less rainfall over the equatorial Southeast Asia region, including Singapore. During this period, generally fair and warm weather can be expected on some days due to stable atmospheric conditions arising from the presence of dry air over Singapore and the surrounding region. On some days in the fortnight, localised short-duration showers, at times with thunder are expected over a few parts of the island in the late morning and early afternoon. In addition, island-wide thundery showers with occasional gusty winds due to Sumatra squalls can be expected in the morning on one or two days. Overall, the rainfall over Singapore for July 2021 is forecast to be above normal.
3 On most days in the fortnight, the daily temperature is forecast to range between 25°C and 34°C. The daily maximum temperature could reach around 35°C on some days, particularly when there are few clouds in the sky. Warm and humid night with minimum night-time temperatures of up to 28°C can be expected on some days, particularly in the eastern and southern coastal areas when prevailing winds blowing from the southeast bring warm, humid air from the surrounding seas.
REVIEW (1 – 15 July 2021)
5 In the first fortnight of July 2021, Southwest Monsoon conditions continued to persist in the region with the low-level winds blowing mostly from the southeast or southwest, and from the west on a few days.
6 In the first two weeks of the month, thundery showers fell over parts of the island between the late morning and afternoon on most days due to strong day-time heating of land areas. On a few days, large scale convergence of winds over Singapore and the surrounding vicinity brought widespread moderate to heavy thundery showers and gusty winds followed by light to moderate rain for most parts of the day, particularly on 12 July and 13 July 2021. The daily total rainfall of 114.2mm recorded at Bukit Panjang on 13 July 2021 was the highest daily total for the first half of July 2021. The highest daily total rainfall from the widespread rain on 12 July was 100.2mm at Ulu Pandan. At the Changi climate station, the total rainfall of 183.8mm recorded in the first fortnight of July 2021 was higher than the average monthly rainfall of 146.6mm for July.
7 The first half of July 2021 was wetter, and cooler compared to June 2021. In the past two weeks, there were only two days where the daily maximum temperature across the island was above 34°C. During the period, the highest daily maximum temperature was 35.0°C recorded on 9 July 2021 at Marina Barrage while the lowest daily minimum temperature was 22.5°C recorded at Admiralty on 13 July 2021.
8 Well above-average rainfall was received across the island in the first fortnight of July 2021. The highest rainfall anomaly of 318% above average was recorded at Tai Seng. The anomaly was lowest at Jurong at 53% above average.
CLIMATE STATION STATISTICS
Long-term Statistics for July
(Climatological reference period: 1991 – 2020)
|Average daily maximum temperature||31.4 °C|
|Average daily minimum temperature||25.4 °C|
|Average monthly temperature||28.2 °C|
|Average rainfall||146.6 mm|
|Average number of rain days||14|
Historical Extremes for July
(Rainfall since 1869 and temperature since 1929)
|Highest monthly mean daily maximum temperature:||32.4 °C (1997)|
|Lowest monthly mean daily minimum temperature:||22.9 °C (1975)|
|Highest monthly rainfall ever recorded:||527.3 mm (1890)|
|Lowest monthly rainfall ever recorded:||12.2 mm (2019)|