Singapore endured a year of climatic extremes in 2024, tying with 2016 and 2019 as the warmest on record with an annual mean temperature of 28.4°C, according to the Meteorological Service Singapore (MSS). From scorching heatwaves to the wettest November in over four decades, the city-state grappled with weather patterns that tested infrastructure and raised questions about the long-term impacts of global warming. While rising temperatures are a clear symptom of climate change, experts caution that linking specific rainfall events to it remains complex due to natural variability and regional climate drivers.
The year saw temperature records shattered, with December 7 marking the hottest December day ever recorded at 36.2°C in Paya Lebar. Meanwhile, an 18-day dry spell in July—the longest since 2019—saw daily highs between 32.8°C and 35.2°C, and even nights offered little relief with lows above 28°C in most areas. Yet, amid the heat, rainfall patterns swung wildly, with total precipitation for the year reaching 2,739.8mm, well above the long-term average of 2,534.3mm. These extremes, detailed in the MSS’s annual climate assessment report released on 23 March, paint a picture of a city navigating an increasingly unpredictable climate.
Record-Breaking Heat and Dry Spells
The heat was unrelenting in 2024, with July and December emerging as the warmest on record for those months. The MSS report ties the warmer-than-usual conditions to the lingering effects of an El Niño phase, which persisted from mid-2023 to April 2024. This global climate phenomenon, characterized by warmer sea surface temperatures in the tropical Pacific, often brings drier and hotter weather to South East Asia. During the July dry spell, influenced by tropical cyclones in the South China Sea, including Typhoon Gaemi, stronger winds carried drier air into the region, exacerbating the heat. 
December, typically one of the cooler months due to the north-east monsoon, defied expectations. Despite being 30% drier than average, it still recorded the unprecedented high of 36.2°C. For residents, the combination of heat and humidity made daily life a challenge, with many turning to air conditioning and public cooling spaces for respite. The persistent warmth over the past decade—2024 being the fourth consecutive year of record-high decadal mean temperatures—underscores a troubling trend for a city already vulnerable to urban heat island effects.
Erratic Rainfall: From Deluge to Drought
Rainfall in 2024 was a story of extremes. November stood out as the wettest in over 40 years, with an island-wide average of 419mm, driven in part by the Madden-Julian Oscillation (MJO), a weather phenomenon that brings enhanced rainfall as it moves eastward across the equator. The MSS estimates that the MJO contributed to 42% of November’s downpours. Yet, just a month later, December’s rainfall plummeted below average, capping the year with an unusually dry note.
Significant rain events also left their mark. On 17 September, a Sumatra squall—a line of thunderstorms originating over Sumatra or the Strait of Malacca—swept across Singapore in just 90 minutes, bringing thundery showers and gusty winds peaking at 83.2km/h on East Coast Parkway. Though the average rainfall was only 10.3mm, the storm’s ferocity felled over 300 trees and caused temperatures to plummet from 30°C to 25°C in mere minutes. A separate event on 14 October saw midnight thunderstorms persist into the afternoon, triggering flash floods in areas like Tampines and Bukit Timah.
These sudden shifts highlight the variability of Singapore’s tropical climate, heavily influenced by large-scale drivers like the El Niño-Southern Oscillation. As MSS noted to The Straits Times, “Although we project more frequent extreme rainfall patterns in the long term, individual rainfall events cannot be attributed directly to climate change.”
Climate Change: A Signal Amid the Noise
While the link between 2024’s rainfall anomalies and climate change remains unclear, the soaring temperatures align with global warming trends. Experts emphasize the difficulty of detecting climate change’s “fingerprints” on specific weather events in the tropics, where natural variability often overshadows long-term signals. Dr Koh Tieh Yong, co-chair of the World Climate Research Programme’s Asian-Australian Monsoon working group, explained that rainfall fluctuations are tied to the redistribution of water vapour rather than a simple increase or decrease in precipitation. “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” he told The Straits Times.
This redistribution, driven by evolving wind patterns and vertical airflow, can disrupt regional and seasonal rainfall, leading to months of surplus or deficit in specific locations. For Singapore, a small island with limited natural buffers, such unpredictability poses risks to urban planning, water management, and public safety. Flash floods, like those on 14 October, strain drainage systems, while prolonged heatwaves increase energy demands and health risks.
Looking Ahead: Adapting to Uncertainty
Singapore’s experience in 2024 reflects broader challenges faced by South East Asian nations as they confront a warming world. The government has long prioritized climate resilience, with initiatives like the Singapore Green Plan 2030 aiming to enhance urban cooling, improve flood defenses, and reduce carbon emissions. Yet, as weather patterns grow more erratic, the balance between mitigation and adaptation becomes ever more critical.
For now, residents and policymakers alike are left to grapple with the immediate impacts of a hotter, less predictable climate. As Dr Koh’s remarks suggest, understanding the full scope of climate change’s influence on local weather will take time and sustained effort. Until then, each record-breaking temperature or unexpected deluge serves as a reminder of the urgent need to prepare for a future where such extremes may become the norm.
