What’s happening: Indonesia wildfires worsen regional air quality

Wildfires are driving a regional haze event

Indonesia is experiencing one of its worst wildfire seasons in over a decade. Estimates suggest wildfires in 2026 have burned nearly 900,000 hectares countrywide. Aside from the direct risks for local populations, the smoke has caused widespread business and travel disruption, including airport suspensions in parts of Kalimantan and Sumatra.

The resulting transboundary haze has affected multiple countries across Southeast Asia. Concern over the severity of the situation prompted the ASEAN Specialised Meteorological Centre (ASMC) to activate Alert Level 3 for the southern ASEAN region, the highest level, on 26 August. 

In the Philippines, air quality reportedly reached “unhealthy” levels on 1 September, prompting class suspensions in parts of Metro Manila. “Unhealthy” to “hazardous” air quality has been consistently reported in parts of Malaysia, particularly in Sarawak, where cases of asthma and conjunctivitis have increased countrywide. Singapore has similarly recorded periodic episodes of “unhealthy” air quality over recent weeks. 

The health burden is also increasing in Indonesia. Between 1 and 9 September, the Ministry of Health recorded over 113,000 cases of respiratory infections associated with deteriorating air quality, more than double the approximately 50,000 cases recorded between July and August.

Dry conditions and El Niño are sustaining wildfire activity

The increase in wildfire activity in Indonesia has been driven by persistently dry weather conditions. Forests and tropical peatlands are particularly vulnerable during prolonged dry periods, with peatland fires capable of burning underground for extended periods and proving difficult to detect and extinguish. 

Human activity, including peatland drainage, land clearing, and deforestation, continues to increase wildfire susceptibility.

Broader climatic conditions are also contributing to the severity of the outbreak. The current El Niño event has produced warmer temperatures and reduced rainfall across parts of Southeast Asia, creating conditions that favour both the ignition and spread of wildfires. As a result, Indonesian authorities are likely to face continued challenges containing fires while conditions remain favourable.

For organisations, the most immediate impacts are operational and health-related. Reduced visibility has already disrupted transport operations, including at regional airports such as Sultan Mahmud Badaruddin II Airport (PLM) and Tjilik Riwut Airport (PKY), while school closures, work-from-home arrangements and other disruptions have become more common across affected areas.

Medical risks have also increased, particularly for children, older adults and individuals with underlying heart or lung conditions. While haze conditions are most severe across Borneo and Sumatra, regional exposure continues to fluctuate depending on hotspot activity and prevailing wind conditions. Short-term exposure can irritate the eyes and respiratory system and place additional strain on the heart, while longer-term exposure may elevate cardiovascular and respiratory health risks.

Outlook

Most likely scenario

Wildfire activity and associated haze are likely to persist into November as dry conditions, rainfall deficits and El Niño continue to support favourable fire conditions.

While the inter-monsoon period could temporarily reduce risks if heavy rainfall occurs over hotspot areas, until the wildfire activity subsides, regional air quality is unlikely to sustainably improve.

 Firefighter responses are also likely to provide localised improvements while not necessarily shifting the overall trend. 

Regional organisations and personnel should anticipate continued fluctuations in air quality as long as transboundary haze poses an active risk.

Recommended actions

• Review and be prepared to activate emergency and business continuity protocols, particularly for medically vulnerable personnel and operations in haze-affected areas.
• Monitor wildfire activity, haze forecasts and local air quality conditions in areas of operation, using reliable sources such as local meteorological agencies and the ASEAN Specialised Meteorological Centre (ASMC).
• Review travel and operational plans regularly and account for the potential for short-notice disruption, including at regional airports and transportation networks.
• Ensure medical risk assessments are conducted for personnel operating in haze-affected areas and consider additional protective measures, including wearing face coverings and/or limiting outdoor activity during periods of unhealthy or hazardous air quality.
• Provide targeted medical guidance to personnel with underlying respiratory or cardiovascular conditions before travel to affected locations.

For risk managers: Configure Sentinel to receive ongoing monitoring and reporting on wildfire and haze developments across Southeast Asia.

For organisation-specific guidance: Contact the Healix GSOC for tailored assessment and advice.