Trend analysis nationwide shows East Malaysia warming faster
The heat is upon us,
with areas across Malaysia hitting Level 1 and Level 2 heatwave status since March.
The Meteorological Department (MetMalaysia) has warned that the hot weather is expected to persist until the South-West Monsoon descends in June.
Level 1 status is issued when the daily maximum temperatures reach 35°C to 37°C for at least three consecutive days, while Level 2 is for temperatures ranging between 37°C and 40°C.
A Level 3 heatwave (temperatures exceed 40°C for three consecutive days) is possible if a strong El Nino occurs, MetMalaysia added.
While this hot and dry weather is typical during the monsoon transition phase, it is occurring within a broader pattern of rising global temperatures.
The United Nations’ World Meteorological Organisation (WMO) said in its annual report that the amount of heat trapped by the earth reached record levels in 2025.
It confirmed that 2015–2025 is the warmest 11-year period on record, and that 2025 was the second or third hottest year at about 1.43°C above the 1850–1990 average.
Under a stable climate, incoming energy from the sun is about the same as the amount of outgoing energy, but increasing concentration of heat-trapping greenhouse gases has upset this equilibrium. This energy imbalance reached a new high in 2025, the agency said.
Closer to home, historical weather data from 1950 to 2025 shows the same upward trajectory.
An analysis of temperature records in 23 locations across Malaysia by Dr Zulfaqar Sa’adi for StarESG displayed the same “significant warming” trend.
“When we look at the top 10 hottest years for each city, the lists are almost entirely dominated by the last decade, with 2024 standing out as the record-breaker for nearly 80% of the country,” said the senior lecturer at the Centre for Tropical Climate Change System of Universiti Kebangsaan Malaysia’s Institute of Climate of Change.
“This suggests that what we once considered an ‘extreme’ temperature in the past is becoming our new ‘normal’ baseline.”
East Malaysia warming faster
Dr Zulfaqar zoomed in on the temperature trend of 23 locations in Malaysia using data from ERA5, which is produced by the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts.
One fact that stood out to him was that cities in East Malaysia are warming faster than the rest of the country.
Labuan, Kota Kinabalu and Miri are leading this surge, with warming rates of up to 0.15°C per decade, nearly double the rate seen in some cities in Peninsular Malaysia, like Shah Alam, he said.
Providing an explanation, Dr Zulfaqar said East Malaysia shows a higher climate sensitivity because over the last decades, it is transitioning from a naturally lush, forested landscape into a more developed one.
Historically, Borneo’s dense rainforests acted as a massive, natural “air conditioner”, keeping the region significantly cooler and more humid.
“As global temperatures rise and these forests are cleared for plantations or urban use, that cooling shield disappears. This causes a more violent ‘temperature jump’ compared to the peninsula, where many areas had already been developed decades ago.
“Essentially, because East Malaysia started from a cooler, natural baseline, it is feeling the shock of warming much more intensely, leading to a faster and steeper climb in record-breaking heat,” he said.
Dr Zulfaqar also noted that across Malaysia, historical “cool” years from the 1950s through the 1980s have been completely erased from the record books, replaced by a relentless string of highs in 2016, 2019, 2024 and 2025.
“This isn’t just a series of hot and dry spells, it is a fundamental rewriting of the Malaysian thermal baseline, where record-breaking temperatures have shifted from being rare events to an annual expectation,” he said. Compound weather uncertainty
Dr Zulfaqar highlighted that the entire yearly average is climbing, instead of just having a few particularly sweltering months before the rains arrive.
“This means that even our ‘cool’ rainy months are becoming warmer than they were 30 years ago.”
While a particularly hot year in the past was usually tied to a specific climate event like a strong El Nino, the senior lecturer said the top 10 hottest years are now packed so closely together in the 2010s and 2020s that “record breaking” has become a redundant term.
“It is simply the new atmospheric reality for Malaysia.
“We aren’t just experiencing hotter peaks, we are losing our cooler troughs,” he explained.
As a climate expert, Dr Zulfaqar wished humans had a clearer answer to exactly how extreme events like heatwaves, heavy rainfall and droughts combine and hit specific places at specific times.
“We already know the world is warming, and we can see clear trends. But what is still difficult to predict is when and where multiple extremes will happen together,” he said. “For example, a heatwave followed by very low rainfall, or intense rain occurring after a long dry period. These combined events are often the most damaging to water resources, agriculture and daily life.”
This uncertainty matters a lot for countries like Malaysia, he said, as even a small change in timing or intensity can mean the difference between manageable weather and serious flooding or water shortages.
“While climate science has made huge progress, improving our ability to pinpoint these compound extreme events at the local level is something many scientists, including myself, are still working hard to understand.”
To see the weather trend in your city, visit thestar.com.my/esg for the interactive version of this story.
