Tourists, along with residents of the city, have been told to minimise their exposure to the smog, and to avoid outdoor activities, putting many of the city's attractions off-limits.
The Singapore Flyer ferris wheel suspended operations yesterday, while the city's famous skyscrapers, and the Gardens by the Bay horticultural project, are shrouded in haze.
Outdoor attractions across the city, including the Adventure Cove Waterpark, have seen a dip in visitor numbers, Channel News Asia reports, and tour operators have been forced to adjust holiday itineraries, substituting outdoor activities for indoor ones.
At least one sightseeing company, DUCKtours, has cancelled its trips, while Universal Studios Singapore has had to cancel some outdoor shows.
The smog has hit small businesses too, with one restaurant reporting an 80 per cent decline in visitors.
Meanwhile, Changi Airport is increasing the time between takeoffs and landings as a precautionary safety measure, although no delays have been reported.
Michael Ross, a 44-year-old Briton and a former resident of Singapore, is due to fly to the city-state on Saturday for a family holiday.
“We did plan to spend four or five days in Singapore and visit Gardens by the Bay, the Singapore Flyer and the high-rise pool at Marina Bay Sands,” he said. “Now I am just trying to find us flights out of there and over to Cambodia for a few days instead.
“We had haze there before, but the levels seen in the last day or two are way beyond anything we experienced.”
Unfortunately Britons due to travel to Singapore will be unable to cancel their trip free of charge because of the pollution. Tour operators and airlines are under no obligation to offer a refund, or even alternative dates, unless the Foreign Office advises Britons against visiting the country.
Its advice currently states that Singapore “is experiencing high levels of pollution from land clearance fires in Indonesia - you should monitor the Pollutant Standards Index (PSI) updates and health advisories from the Singapore National Environment Agency (NEA).”
The NEA advises anyone with heart or lung diseases, children and the elderly to stay indoors, adding that “everyone else should avoid all physical activity outdoors”.
The Singapore Tourist Board said the country remains open to tourists but also advised caution.
"Tourists are advised to minimise their exposure by limiting prolonged or heavy outdoor activities," said a spokesman."In particular, children, the elderly and those with heart or lung diseases, should seek medical treatment early if they feel unwell. STB is keeping a close watch on the situation."
In an attempt to tackle the smog, President Susilo Bambang Yudhoyono has ordered disaster officials to "mobilise all the country's resources" to extinguish the fires that are causing the problem. Indonesia's national disaster agency said two helicopters with cloud-seeding equipment were sent to Sumatra, where hundreds of hectares of carbon-rich peatland are ablaze.