- Monsoon Update
(Updated on 25 November 2019)
Singapore and the surrounding region are in the Northeast Monsoon season that set in around mid-November 2019. The season is forecast to lasts until March 2020 and typically has two phases, a wet phase from December to January followed by a dry phase from February to March. During the season, the prevailing low level winds usually blows from the northeast or northwest.
During the wet phase of Northeast Monsoon season, Singapore can expect short-duration moderate to heavy thundery showers mostly in the afternoon on most days. On some of these days, the showers could extend into the evening due to a convergence of winds over Singapore and the surrounding vicinity. In addition, there can be a few episodes of monsoon surges that usually brings prolonged, widespread rain showers lasting between two and five days. Occasionally windy conditions and cooler temperatures usually accompanies the rain showers during the surge episodes.
In the first week of December 2019, a monsoon surge is likely to affect Singapore and the equatorial South China Sea region. The surge is likely to bring a few days of cooler temperatures, occasionally windy conditions and widespread moderate to heavy rain to Singapore and the surrounding region. During the period of the surge, the daily maximum temperature over Singapore could reach a high of around 29°C and the daily minimum temperature could drop to a low of around 22°C. December 2019 is likely to be wetter-than-usual over Singapore and the surrounding vicinity.
The prevailing wet phase of the Northeast Monsoon season usually peaks in January before gradually easing into the dry phase of the Northeast Monsoon season in February. Northeast Monsoon conditions are likely to gradually transition to the inter-monsoon conditions around mid-March 2020, during which Singapore can expect localised short-duration thundery showers in the afternoons due to strong daytime heating of land areas.
For the Dec-Jan-Feb 2019/2020 Northeast Monsoon season, rainfall and temperature over Singapore and the surrounding equatorial Southeast Asia region is likely to be above-normal.
In December, the monsoon rain band typically lies over the equatorial belt, and based on long-term statistics* at our climate station, December is Singapore’s wettest month of the year. In contrast, February is generally our driest month of the year as the monsoon rain band typically lies south of the Equator. While February may be drier compared to December and January, showers can still be expected over parts of Singapore on some days due to daytime heating of land areas. The number of rain days in February is typically low when compared to the months during the wet phase of the Northeast Monsoon season.
Table 1 shows the long-term rainfall and temperature statistics for December to March at our climate station.
|Average Monthly Rainfall Total (mm)||318.6||234.6||112.8||170.3|
|Average number of rain days (Days with 0.2mm or more of rainfall)||18||13||8||13|
|Average Daily Maximum Temperature (°C)||30.2||30.4||31.7||32.0|
|Average Daily Minimum Temperature (°C)||24.0||23.9||24.3||24.6|
Table 1: Long-term rainfall and temperature statistics for December – March
For the latest weather forecast, including heavy rain warnings, please visit our MSS website (www.weather.gov.sg), NEA website (www.nea.gov.sg), download the myENV app., Weather@SG app, weather information hotline at 65427788, through following NEA’s twitter via @NEAsg or from radio broadcasts.
 A monsoon surge refers to the strengthening of northeasterly winds blowing from a strong high-pressure system over the northern Asian continent toward the South China Sea. The surge typically brings periods of prolonged widespread rain and windy conditions to the surrounding region including Singapore and Peninsular Malaysia. (Further information on monsoon surge is available at www.weather.gov.sg/learn_weather_systems/).
 Based on 30-yr climatological reference period (1981- 2010)