FOR the republic, 2024 was a year of record-breaking temperatures and unusual rainfall patterns – from July logging its first dry spell since 2019, to soaring temperatures and less rain in December.
The wettest November in more than 40 years was also recorded in 2024, while two unusual episodes in September and October brought intense rain in the preceding months, the weatherman’s annual climate assessment report showed.
Across the whole year, total rainfall at 2739.8mm was higher than the long-term average of 2534.3mm, said the report released on March 23.
While soaring mercury is a symptom of global warming, the unusual rainfall patterns of 2024 could not be linked directly to climate change, the Meteorological Service Singapore (MSS) told The Straits Times.
This is because Singapore’s rainfall is highly variable, with strong dependence on large-scale climate drivers such as the El Nino-Southern Oscillation – a global climate cycle involving changes in winds and sea surface temperatures in the tropical Pacific Ocean. This driver comprises the warming El Nino and rainy La Nina climate phenomena.
MSS added: “Although we project more frequent extreme rainfall patterns in the long term, individual rainfall events cannot be attributed directly to climate change.”
But overall – as revealed by the MSS in January – 2024 was the warmest year in Singapore, tying with 2019 and 2016, with temperatures hitting an annual mean of 28.4˚C.
2024 also marked the fourth year in a row that Singapore’s mean temperature over a decade reached a new high. The year also saw the warmest July and December on record.
The warmer-than-usual conditions are likely associated with the El Nino period, which lasted from the second-half of 2023 to around April 2024.
While December 2024 was one of the cooler months of the year, it also broke temperature records, with the mercury hitting a scorching 36.2˚C in Paya Lebar on Dec 7.
Experts say it is tricky to detect the fingerprints of climate change on rain events here.
Dr Koh Tieh Yong from the World Climate Research Programme said: “Many more years of concerted data collection and analysis are needed to tease out the man-made signal of climate change from the natural ‘noise’ of our tropical rainfall.”
Rainfall fluctuations amid climate change are linked to the redistribution of water vapour rather than an overall increase or decrease in downpours, noted Dr Koh, who co-chairs the research programme’s Asian-Australian Monsoon working group.
Water vapour in the air is redistributed as winds and vertical airflow evolve. This then upsets regional and seasonal rainfall patterns in the tropics, he explained. — The Straits Times/ANN
