Why is it hazy?
Haze mostly comes from fires in Sumatra and Kalimantan, especially peat fires, carried by wind to Singapore and Malaysia; drought and El Niño make it worse and rain eases it. Each factor below has live data and links to the original sources.
Singapore now · as at 10:00 SGT
Check your area →100 µg/m³ · Elevated (1-hour PM2.5, NEA official, worst region)
Fires in central Sumatra (Riau and Jambi) and Singapore's hazeCentral Sumatra, mainly Riau and Jambi, lies about 280 km south-west of Singapore. When fires there are active and the wind blows from the south-west to south, smoke can reach Singapore within hours.Fires in South Sumatra and Singapore's hazeSouth Sumatra is roughly 550 km south of Singapore. It is a major fire region in dry years; southerly winds, which are common in the dry season, can carry its smoke north toward Singapore and Peninsular Malaysia.Fires in Kalimantan and Singapore's hazeKalimantan (Indonesian Borneo) is more than 1,000 km east of Singapore. Its smoke tends to reach Singapore and Malaysia when winds blow from the east or south-east, and it often affects Sarawak and Brunei first.How wind carries smoke to SingaporeSmoke travels with the wind at roughly 1–2 km altitude, not at ground level. If that wind blows from a fire region toward you, haze can arrive within hours to a day; if it blows away, air often clears even while fires continue.Dry weather and El Niño: why haze years happenHazy years follow dry years. El Niño and a positive Indian Ocean Dipole reduce rainfall over Indonesia, which dries peat and forest so fires spread easily and are hard to put out.Why peat fires make such dense hazePeat is partly decayed plant matter stored in waterlogged soil. Once drained it can burn and smoulder underground for weeks, releasing far more smoke per fire than ordinary vegetation fires and making it hard to extinguish.Does rain clear haze? What showers can and cannot doRain helps: it washes fine particles out of the air and can dampen fires. But a short shower rarely ends a haze episode, because new smoke keeps arriving while fires burn.