🇲🇾Malaysia

Malaysia lies just north of the equator as a Southeast Asian country (approximately 330,803 km²) divided by the South China Sea into Peninsular Malaysia (the Malay Peninsula bordering Thailand and Singapore) and East Malaysia on the northern part of Borneo bordering Indonesia and Brunei, comprising Sabah and Sarawak. Malaysia is one of the world's megadiverse countries, supported by extensive rainforests.

Topography includes the Titiwangsa Range running down Peninsular Malaysia, Mount Tahan at 2,187 m in the Tahan Range, the Crocker Range of Sabah rising to Mount Kinabalu at 4,095 m (the country's highest peak and Borneo's tallest mountain), the Iran Mountains of Sarawak, deep lowland and peat swamps, and a 4,675 km coastline.

The climate is uniformly tropical: tropical rainforest (Af) across most of the country and tropical monsoon (Am) with a short drier season in the far northwest of the peninsula, with the northeastern peninsular coast in Kelantan and Terengganu receiving concentrated heavy rainfall during the northeast monsoon from October to March, and much cooler conditions near Mount Kinabalu's summit.

Kuala Lumpur has daytime highs of about 32–34°C and nights of 24–25°C year-round, a remarkably narrow monthly range, with 2,400–2,850 mm rainfall fairly evenly distributed but peaking in two inter-monsoon seasons. George Town on Penang sees highs of 31–33°C and nights of 24–25°C with 2,330–2,400 mm. Johor Bahru sees highs of about 31–32°C and nights around 23–24°C. Kota Kinabalu in Sabah sees highs of 31–33°C and nights around 24°C with 2,640 mm. Kuching in Sarawak sees highs of 30–33°C and nights around 23–24°C with 4,230 mm, the wettest populated area in Malaysia. Sandakan sees highs of 30–33°C and nights of 24–25°C with 3,140 mm.

Malaysia faces recurring flood hazards, transboundary air pollution, and climate-driven marine threats. The December 2014 floods, which hit Kelantan hardest, were the worst in decades, with more than 200,000 people evacuated nationwide. The December 2021 Klang Valley floods damaged Kuala Lumpur. Indonesian forest fires in 2015 created severe haze conditions, closing schools and disrupting regional aviation.

The April 2024 Southeast Asian heatwave brought heat-wave alerts across Malaysia. Coral bleaching episodes have threatened marine ecosystems. Sea-level rise is increasingly threatening coastal villages. These hazards reflect Malaysia's vulnerability to extreme weather, transboundary pollution, and climate-driven ocean changes. These events underscore growing climate risks across precipitation, air quality, thermal, and coastal systems.

Our archive covers 86 Malaysian cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Bercham, with average highs around 32.5°C, while Wangsa Maju has the coldest January nights, with average lows near 21.6°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.6°C.