Some years it comes, and some years it does not. But, drifting up and across the Strait of Malacca, it can hang in the air for weeks on end over cities such as Singapore and Kuala Lumpur - regional economic hubs that host two of the world’s busiest airports.
Southeast Asia’s haze is on the way back and this year’s event is expected to be "severe," according to the Singapore Institute of International Affairs (SIIA), which has been tracking the region’s haze disruptions for almost a decade.
August and September are projected to be the worst months and in turn the worst time of the year to visit, with air turning eye-wateringly and lung-cloggingly unpleasant.
Singapore’s Ministry of Health is telling visitors to expect “irritation of the eyes, nose, and throat” during the haze. And while effects can vary depending on a person’s overall health, anyone out and about for extended periods of time should wear an N95 mask.
While much of the region is seeing daily downpours, a dry spell is expected later in the year due to the combination of an imminent El Niño and a positive Indian Ocean Dipole, a climate phenomenon marked by warmer-than-usual sea surface temperatures.
This raises the danger of forest fires, meaning a "high risk" that Brunei, Indonesia, Malaysia and Singapore are about to see a “severe transboundary haze event.”
The recurring issue has led to tensions between countries in the region, with haze originating in Sumatra often hanging over tiny-but-wealthy Singapore, a travel and investment hub, and disrupting day-to-day life.
Arguably the worst event on record dates to the late 1990s as deforestation, some of it caused by deliberate burning, became widespread across parts of Indonesia and Malaysia to make way for the world’s biggest palm oil plantations.
According to the SIIA, the dipole and the return of El Niño are "expected to create a longer and stronger dry season at a time when fire preparedness could be adversely affected by economic uncertainty."
The rising oil and fertiliser prices following the closure of the Strait of Hormuz have led to increased interest in locally produced alternatives, such as biofuels.
"Rising demand for agricultural commodities and biofuels could increase land-use pressures," the SIIA explained, pointing to man-made pressures that could fuel the problem and a "danger" that some producers "could resort to unsustainable expansion and the use of fire to save costs."
