Many sporting and outdoor events scheduled for this weekend have been cancelled or postponed because of the haze, including Pedestrian Night in Orchard Road tomorrow.
The event, during which the shopping stretch is closed off to vehicles, was called off "out of consideration for the health and safety of our staff, our visitors and all street performers," said a spokesman.
But the in-mall promotions and shopping deals will still be on offer.
Meanwhile, the Bloomberg Square Mile Relay, scheduled to take place yesterday, was postponed. Mr Nick Keller, chief executive officer of organiser Square Mile Sport, said it is still looking for a new date for the race.
NTUC U Family also said yesterday that its family bonding event, U Picnic, which was to take place tomorrow, will be postponed.
Organisers of other events are closely monitoring the haze situation before making a decision.
Said Mr Ang Peng Wee, chairman of the organising committee of the Fina/airweave Swimming World Cup Singapore: "As hosts, we would like to avoid disappointing spectators, fans and the athletes, some of whom are hoping to make the 2016 Rio Olympics qualifying times in this meet.
"However, the health and safety of our athletes, guests, officials, volunteers, spectators and staff is our top priority and, as such, the threat of haze is indeed a worry."
The weekend meet, to be held at the indoor OCBC Aquatic Centre at the Singapore Sports Hub, is to be attended by 263 swimmers from around the world. It is one of the legs in the annual Fina Swimming World Cup from August to November this year. The committee will hold a press conference today about whether the event will go on.
The Singapore Sports Hub Stepper, a stair-climbing event, will be postponed from tomorrow to Oct 31 if the three-hour Pollutant Standards Index exceeds 200.
If that happens, the Light Up Your Life charity run at East Coast Park tomorrow will be cancelled. The organisers, animal welfare group Save Our Street Dogs and Assisi Hospice, said the carnival portion of the event, featuring a dog adoption drive, will continue.