Hotter weather due to El Nino expected in Singapore from July, says Met service

SINGAPORE – Warmer weather is on the cards for Singapore from July, with the Republic’s meteorological service forecasting the return of the sizzling El Nino weather phenomenon.

South-east Asia could also be hit by a more intense El Nino than in previous years, according to some international weather scientists.

El Nino is a climate phenomenon that results in less rain, longer dry spells and higher temperatures for the region. It is caused by a natural cycle called the El Nino-Southern Oscillation, when changes in winds and sea surface temperatures shape weather patterns over the Pacific Ocean, which covers about one-third of the planet.

Since late 2025, Singapore has been experiencing La Nina conditions. La Nina, the opposite phase of the oscillation to El Nino, brings cooler-than-usual weather and more rainfall over Singapore.

Thai news outlet The Nation had in March quoted US-based weather scientists suggesting that an El Nino capable of causing severe and prolonged drought could occur in 2026.

However, it is still too early to predict how serious the event will be for Singapore and the region, local climate scientists and the Meteorological Service Singapore (MSS) told The Straits Times.

Meteorologist Koh Tieh Yong, who is also a member of the Working Group for Asian-Australian Monsoons at the World Climate Research Programme, said El Nino forecasts are known to lack accuracy at this time, when spring arrives in the Northern Hemisphere.

The adjunct associate professor, who teaches meteorology and climate science at the National University of Singapore, said: “So, there may be significant updates to the forecasted El Nino strength in two or three months’ time.”

MSS told ST that models have predicted possible El Nino conditions from July.

“If El Nino does develop, it tends to impact Singapore’s rainfall most during June to October,” said the service, which operates under the National Environment Agency.

It noted, however, that long-term forecasts at this time of the year remain uncertain.

Prof Koh noted that global forecasts from renowned international climate monitoring centres in South Korea, Tokyo and the United States anticipate a moderate El Nino from around May or June, with about 30 per cent chance of the phenomenon being stronger than normal.

He said past moderate-to-strong El Nino events in the last 30 years have shown that there could be 40 per cent to 80 per cent less rainfall for some months in parts of Singapore.

What affects the strength of an El Nino?

The strength of an El Nino event is measured by how much it causes sea surface temperatures in the eastern and central equatorial Pacific Ocean to rise above the long-term average, said Prof Koh.

Some weather scientists have suggested that when sea surface temperatures in key parts of the equatorial Pacific Ocean rise by at least 2 deg C above the normal average, they will trigger what has been colloquially termed as a “super El Nino” that could fuel extreme dry weather and wildfires in South-east Asia.

An El Nino of such a magnitude is rare, occurring every 15 to 20 years, although not on a fixed schedule, according to NTU Earth Observatory of Singapore’s principal investigator, Professor Adam Switzer.

The most recent instance of a strong El Nino occurred between 2015 and 2016, said Prof Koh and Prof Switzer. At that time, the prolonged dry and hot weather caused by El Nino resulted in South-east Asia experiencing its worst haze crisis on record.

The El Nino event then was also considered strong by MSS, which uses the Nino3.4 index to gauge the intensity of the phenomenon. The index compares the sea surface temperature in the central and western tropical Pacific Ocean with its long-term historical average.

MSS said: “During El Nino, temperatures in the central and eastern Pacific Ocean are much warmer than the historical average, while temperatures in the western Pacific Ocean are cooler than average.”

The gradual warming of sea surfaces caused by climate change, however, has made it harder to predict the intensity of El Nino and La Nina events, it noted.

“Without accounting for this long-term warming, we may see slightly higher values of the Nino3.4 index, making El Nino events seem stronger, or La Nina events appear weaker than they are,” MSS said.

El Nino events are considered strong by MSS when the three-month average of the Nino3.4 index exceeds 1.5 deg C.

The El Nino events spanning 2015 and 2016, as well as 1997 and 1998, both logged an index of more than 2 deg C.

Prof Switzer said that generally, drier and hotter conditions brought by El Nino to much of South-east Asia can lower reservoir levels, stress water supplies, reduce crop yields, and increase the risk of drought, forest fires and transboundary haze, especially in Indonesia.

“In the wider region, El Nino can also disrupt fisheries, ecosystems and hydropower generation while raising heat stress for people and cities,” he added.

An interdisciplinary study by researchers from Nanyang Technological University and the City University of Hong Kong published in January found that intensifying El Nino events could reduce life expectancy across high-income Pacific Rim countries.

Based on current climate projections, it estimated economic losses of up to US$35 trillion (S$44.7 trillion) by the end of the 21st century, with most of the monetary burden shouldered by the middle-aged population.

Singapore will be better prepared to manage the health risks of El Nino with its national heatwave response plan unveiled in 2025, said Prof Switzer.

The plan, formulated by the inter-agency Mercury Taskforce, will issue public advisories when a heatwave is forecast and activate measures like the opening of islandwide cooling centres.

MSS said its latest forecast of the El Nino-Southern Oscillation’s effects over the next three to six months will be released on March 20.