SINGAPORE: Following a wet and cool start to the year, the second half of January is expected to be generally dry and warm with highs of about 34°C on a few days.
Daily maximum temperatures in the coming fortnight are also expected to range between 32 and 33°C on most days, the Meteorological Service Singapore (MSS) said on Friday (Jan 15).
On most days in the second half of January, the daily temperatures are forecast to range between 24 and 33°C.
"It is expected to be warm with daily maximum temperatures of around 34°C on days with little or no rain and when winds are light," said MSS.
Short-duration thundery showers due to strong day time heating of land areas can be expected mostly in the afternoon over parts of the island on some days.
With stable atmospheric conditions arising from the presence of a dry air mass over the equatorial Southeast Asia region, Singapore can expect fair and occasionally windy conditions on a few days, said MSS.
While rainfall for the second half of the month is expected to be below normal, MSS added that the overall rainfall for January 2021 is forecast to be well above-normal due to the exceptionally wet weather in the first half of the month.
The prevailing Northeast Monsoon season is also forecast to continue for the rest of January with low-level winds blowing from the northwest or northeast.
In the first half of January, Northeast Monsoon conditions prevailed over Singapore and the surrounding region. During this period, the low-level winds blew mostly from the northeast.
Weather during the first fortnight of January was wet and cool due to a surge of northeast monsoon winds, also known as a monsoon surge. This took place over the equatorial South China Sea region on Jan 1 and Jan 2, and again on Jan 8 to Jan 13.
The New Year weekend surge event brought widespread continuous rain, heavy at times over the island, said MSS.
The highest daily total rainfall recorded on the first two days of the year was 147.3mm at Upper Changi Road East and 210.6mm at the Changi climate station.
The total rainfall at the climate station on Jan 2 was slightly less than the record high in a day for January at 216.2mm on Jan 30, 2011.
The second monsoon surge event started on Jan 8 and persisted over the equatorial South China Sea for the next few days before it eased on Jan 13. The surge, coupled with large-scale convergence of winds over Singapore and the surrounding area, brought windy and rainy weather during the period.
MSS said it was particularly windy with continuous rain, heavy at times over the island, on Jan 10. The highest daily total rainfall of 204.0mm recorded during the six-day surge event was Jan 10 at Changi.
At the Changi climate station, the total rainfall in the first two weeks of this month was 648.4mm, which ranks January 2021 as the wettest January in the last 30 years. This surpasses the 600.9mm recorded in January 2004.
Based on long term statistics, MSS said January 2021’s total rainfall to date of 648.4mm also ranks January 2021 as the second wettest January since rainfall records in Singapore began in 1869. The wettest ever January in Singapore on record is January 1893 with a monthly total of 818.6mm.
MSS data also showed that the first fortnight of January this year was also exceptionally cool due to the cloudy and rainy weather arising from the two monsoon surge events.
The daily maximum temperature was below 30°C on all days in the fortnight except for Jan 5, Jan 6 and Jan 14.
The daily minimum temperature dipped to 23°C and below on the first five days of the year. The lowest daily minimum temperature in the first fortnight of the month was 21.1°C, recorded on Jan 2 at Newton.
It was also relatively windy in the first half of the month.
At the Changi climate station, wind gusts of up to 46.9kmh were recorded on Jan 12 during the second monsoon surge event. The highest ever recorded wind gust for January at the Changi climate station was 73.4kmh.
The highest maximum wind gust recorded islandwide in the first two weeks of the year was 70.2kmh at Admiralty on Jan 12.
MSS added that Singapore also received significantly above normal rainfall in the first fortnight of January with the highest anomaly of 511 per cent above average recorded at Changi. The anomaly was lowest at Jurong at 153 per cent above average.