Haze Situation Singapore
Regional haze, hotspots & smoke haze forecast
The ASEAN Specialised Meteorological Centre (ASMC), hosted by MSS/NEA, monitors regional fires and transboundary smoke haze. For live hotspot maps and the latest haze situation, visit the ASMC website or the official haze microsite.
When Does Haze Affect Singapore?
Southwest Monsoon
June – September
Traditional haze season. Dry weather over Sumatra and Kalimantan increases fire risk; prevailing winds blow smoke toward Singapore.
Northeast Monsoon
December – March
Rainy season typically suppresses fire activity. Haze is rare during this period, though occasionally volcanic ash can affect visibility.
How Haze Forms & Reaches Singapore
Forest & Land Fires
Fires burn peatland and forests in Sumatra, Kalimantan and other parts of ASEAN.
Smoke Particulates Released
Fine particles (PM2.5) rise from burning vegetation and peat.
Winds Carry Smoke
Prevailing winds transport smoke hundreds of kilometres across the region.
Haze Reaches Singapore
PSI and PM2.5 climb, sometimes into Unhealthy or Hazardous bands.
Regional Hotspot Monitoring
The ASMC uses satellite imagery to detect hotspots — areas of unusually high temperature that usually indicate fires. Hotspots are not always fires (cloud reflections and industrial activity can produce false positives), and cloud cover can hide real fires, but a cluster of hotspots in dry weather is a strong early warning of haze.
High Alert
Many hotspots across Sumatra or Kalimantan with dry weather and winds blowing toward Singapore.
Monitor
Scattered hotspots with mixed cloud cover or unfavourable wind direction.
Low Risk
Few or no hotspots, or rainy conditions suppressing fire activity.
Major Haze Episodes Affecting Singapore
| Year | Peak 24-hr PSI | Source Region | Notes |
|---|---|---|---|
| 1997 | 226 | Sumatra & Kalimantan | One of the worst on record; linked to a strong El Niño and prolonged drought. |
| 2013 | 401 (“PSI record”) | Central Sumatra (Riau) | The “haze crisis”: PSI crossed 400 for the first time, prompting the Transboundary Haze Pollution Act. |
| 2015 | 341 | Sumatra & Kalimantan | Another strong El Niño year; studies estimated S$1.8 billion in economic losses in Singapore. |
| 2019 | ~164 | Kalimantan & Sumatra | Mid-September spike; schools scaled back outdoor activities. |
PSI values shown are the peak 24-hour national readings reported by NEA during each episode. The worst episodes typically coincide with strong El Niño years and prolonged dry spells over southern Sumatra and Kalimantan.
Haze Safety Tips
If PSI is Moderate (51–100)
- Normal activities can continue
- Sensitive groups should watch for symptoms
If PSI is Unhealthy (101–200)
- Reduce outdoor physical exertion
- Children, elderly and pregnant women should stay indoors
- Drink plenty of water
If PSI is Very Unhealthy (201–300)
- Avoid outdoor activity
- Wear N95 masks if you must go out
- Use air purifiers indoors
If PSI is Hazardous (> 300)
- Minimise all outdoor activity
- Seal doors and windows
- Seek medical attention if unwell
Related Information
Haze in Singapore — a regional problem
Haze in Singapore is almost always transboundary: smoke from land and forest fires in Sumatra, Kalimantan and other parts of ASEAN is carried to Singapore by prevailing winds. The worst haze episodes — 1997, 2013, 2015 and 2019 — saw the 24-hour PSI climb well into the Hazardous range and disrupted daily life across the island.
What is the haze season in Singapore?
The traditional haze season runs from June to September during the Southwest Monsoon, when dry conditions prevail over southern Sumatra and Kalimantan and prevailing winds blow from the southwest. The Northeast Monsoon (December–March) brings rain and typically suppresses fire activity.
How to monitor the haze situation
Track the regional haze situation using three tools: the 1-hour PM2.5 band on the air quality page for the fastest signal, the 24-hour PSI for the official health advisory, and the ASMC hotspot map for early warning of fires that may affect Singapore in the days ahead.
When will the haze end?
Haze typically eases when rains return to the fire source regions or when prevailing winds shift away from Singapore. The ASMC's daily outlook and the NEA haze advisory give the most reliable guidance on the haze forecast for the coming days.
NEA Weather SG republishes haze guidance based on publicly available data from NEA, MSS and the ASEAN Specialised Meteorological Centre. We are not affiliated with NEA. For official information, visit haze.gov.sg or asmc.asean.org.