🇲🇾Malaysia

Malaysia lies at 0°51′–7°22′N 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 third of Borneo bordering Indonesia and Brunei, comprising Sabah and Sarawak. This produces an extraordinary biodiversity supported by 130-million-year-old rainforests.

Topography includes the Titiwangsa Range running down Peninsular Malaysia with Mount Tahan at 2,187 m, 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 with no significant dry season — tropical rainforest (Af) across nearly all the country, with a small tropical monsoon (Am) tendency on the northeastern peninsular coast in Kelantan and Terengganu where the northeast monsoon from November to March brings concentrated heavy rainfall, and a tundra (ET) tendency on Mount Kinabalu's summit.

Kuala Lumpur averages 27°C year-round with a remarkably narrow 26–28°C annual range and 2,580 mm rainfall fairly evenly distributed but peaking in two inter-monsoon seasons. George Town on Penang averages 28°C with 2,640 mm. Johor Bahru averages 27°C with 2,580 mm. Kota Kinabalu in Sabah averages 27°C with 2,640 mm. Kuching in Sarawak averages 27°C with 4,090 mm — among the world's wettest cities. Sandakan averages 27°C with 3,140 mm.

Malaysia faces recurring flood hazards, transboundary air pollution, and climate-driven marine threats. The December 2014 Kelantan floods were the worst in 30 years, displacing 200,000 people. 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 temperatures above 38°C in Petaling Jaya. Coral bleaching occurred in the Sulu Sea in 2010 and 2024, threatening marine ecosystems. Sea-level rise has accelerated, increasingly threatening coastal villages in Kelantan. These hazards reflect Malaysia's vulnerability to extreme weather, transboundary pollution, and climate-driven ocean changes. Recent acceleration in the frequency and severity of these events underscores 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 warmest July averages occur in Bercham, around 32.5°C, while Wangsa Maju records the coldest January nights 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.