Warm weather expected from Jun to Oct; increased risk of haze affecting Singapore

Prolonged warm and dry weather can be expected from June to October, reported The Meteorological Service Singapore (MSS).

This is a result of El Niño, a naturally occurring climate pattern associated with changes in both the ocean and atmosphere in the equatorial Pacific Ocean. Typically lasting nine to 12 months and occurring every three to five years, it produces widespread and possible severe changes in the global climate.

The drier and warmer conditions can also cause vegetation fires, resulting in an increased risk of haze.

According to MSS, there is a 70 to 80 per cent chance of an El Niño event occurring this year.

There were signs earlier this year that predicted the El Niño condition. One of these indicators is the warmer ocean temperatures observed in the eastern tropical Pacific.

At this stage, there is no indication of the strength and duration of the El Niño. If it occurs, below-average rainfall and warmer temperatures can be expected during the coming months.

El Niño events tend to have the biggest influence on Singapore’s rainfall during the Southwest Monsoon season, with rainfall up to 45 per cent below average.

Its occurrence from June to September 2015 saw an average temperature of 28.8 degrees Celsius, which is a 0.6 degree Celsius increase from its long-term average for that period.

From March to April 2016, Singapore’s average temperature was 29.2 degrees Celsius, making it 1.2 degrees Celsius higher than its long-term average for said period.

2016 and 2019 are Singapore’s hottest years on record.

The weather could be worsened by The Indian Ocean Dipole (IOD), a phenomenon similar to El Niño but takes place in the equatorial Indian Ocean.

Unlike El Niño, it lasts for a shorter period typically ending by December or January. It varies between three phases – positive, negative, and neutral.

Most computer models from global climate centres predict that a positive IOD may develop in the next one to two months.

When this happens, sea surface temperatures in the eastern Indian Ocean are cooler, resulting in less cloud formation and below-average rainfall in the eastern Indian Ocean and surrounding regions including Sumatra, Peninsular Malaysia, and Singapore.

MSS will continue to closely monitor the development of El Niño and IOD as well as the regional weather and haze situation, and provide updates when necessary.

Updates on haze and the El Niño phenomenon are available on the MSS website.