Malaysia's haze: Decades later, why does it keep returning?
From Sarawak in 1997 to Port Klang in 2005, Muar in 2013 and Serian in 2026, PulseKita tracks what happened, how authorities responded and which air-quality records are available.
PulseKita · Reviewed 10 October 2026DOE, MOE, ASEAN and Bernama records
1997Sarawak haze emergency
2005Klang Valley emergency
2013Muar & Ledang emergency
2026Serian emergency
THE STORY BEHIND THE NUMBERS
Multiple generations have lived through Malaysia's haze.
These are distinct events, affected by local conditions, weather, fires and public responses. A reading of 518 in Serian on 4 September 2026 is not interchangeable with a national monthly pollution average.
SOURCE-LINKED CHRONOLOGY
Milestones in Malaysia's haze history
From 1994 to 2026. Each API figure below is a dated reading or reported threshold for a specific place, NOT an annual national maximum.
13 records
1994September 1994
Malaysia
Haze lasts more than a month
DOE records prolonged haze associated with major fires in southern Sumatra and Kalimantan. Dry weather, weak winds and local emissions worsened conditions.
>500IPU / APIReported threshold, not an exact reading
200210 June 2002
Kuala Lumpur
ASEAN signs the haze agreement
ASEAN signs its transboundary haze agreement in Kuala Lumpur, strengthening prevention, monitoring and regional cooperation. It enters into force in 2003.
>500IPU / APIReported threshold, not an exact reading
201414 March 2014
Port Klang & Banting
API exceeds 300 in two locations
DOE records readings above 300 amid haze associated with local forest and peat fires. A total of 203 schools close in Klang and Kuala Langat districts.
>300IPU / APIReported threshold, not an exact reading
201514–18 September 2015
Peninsular Malaysia & Sarawak
34 unhealthy areas and school closures
On 15 September, 34 areas reach unhealthy API levels. DOE records 211 in Banting on 14 September. Schools shut in parts of the Klang Valley and Sarawak.
School closures across states; 37 unhealthy API areas
Reuters reports that school closures on 9 October cover Johor, Melaka, Negeri Sembilan, Selangor, Kuala Lumpur, Putrajaya and Rompin district in Pahang. That morning, 37 areas recorded unhealthy API. Check MOE for any later changes.
Monthly average PM₁₀ and PM₂.₅ concentrations from DOE and DOSM in micrograms per cubic metre (µg/m³). These are not daily API readings.
PM₁₀2017–2024 · 94 recorded months
Latest observed value: 18.9 µg/m³ (2024-12)
PM₂.₅2018–2024 · 84 recorded months
Latest observed value: 11.5 µg/m³ (2024-12)
Malaysia-level monthly averages, not station API or daily readings. Lines break over missing observations. These records do not cover 1997–2015.
Official dataset: OpenDOSM · Monthly Air Pollution ↗. The public dataset covers 2017–2024; missing values are not estimated. Historical API and particulate concentrations measure different things.
UNDERSTANDING THE CAUSES
Why does haze recur?
01
Forest and peatland fires
Historical episodes have been linked to fires in Sumatra, Kalimantan and parts of Malaysia. The specific causes vary by event.
02
Dry weather and wind
Dry spells and wind patterns can intensify or move smoke. DOE links El Niño conditions with the 1997 crisis.
03
Regional cooperation
ASEAN's 2002 agreement supports prevention and response. Ratification alone does not mean haze episodes cease.
Follow local official guidance and reduce outdoor activity when API rises. Children, older adults and people with heart or lung disease are among the higher-risk groups.
DOE's chronology covers 1994–2015. Later events are sourced to Bernama and official statements. Monthly PM comes from data.gov.my; it is not combined with API or used to estimate historical readings.
