PM2.5 annual average (ug/m3) over 5 years City markers indicating 2025 PM2.5 levels, size adjusted for population Malaysia saw a modest decline in its annual average PM2.5 concentration, dropping from 18.3 μg/m3 in 2024 to 16 μg/m3 in 2025. This downward trend was reflected in the capital, Kuala Lumpur, which recorded an 11% decrease, from 17.7 μg/m3 to 15.7 μg/m3, over the levels, maintaining annual averages between 5 and 10 μg/m3. spikes. In February, a regional haze in the state of Penang resulted in a 10% to 26% increase in city average PM2.5 levels relative to 2024.27 Another seasonal PM2.5 spike occurred in July state of Selangor, saw monthly PM2.5 levels up by an average of 28% in July and August. Malaysia's main air pollutant sources include vehicular emissions, industrial manufacturing, and power generation, while transboundary haze from neighboring country peatland and forest the National Clean Air Action Plan (2025-2040) and ASEAN Haze Agreement commitments, fossil fuels still supplied 90% of electricity, sustaining background emissions.3t From July to August 2025, Malaysia faced its worst transboundary haze crisis in years, as forest and peatland fires in Sumatra and Kalimantan sent smoke across borders.32 NASA satelites and the ASEAN Specialised Meteorological Centre (ASMC) detected scattered hotspots in Sumatra's central regions and western Kalimantan, with smoke plumes drifting into Peninsular Malaysia and Sarawak.33 The ASEAN Haze Centre issued an Alert Level 2 on July 19 as fires Annual hours spent at different PM2.5 pollution levels