A change in wind direction has given Singapore some respite from the haze, which threatened to turn very unhealthy early yesterday.
Gusts from the south and south-west had been blowing smoke from burning forests in Sumatra in Indonesia to Singapore, but the winds now come from the south-east, the National Environment Agency said yesterday.
These winds are expected to persist today, it said.
It forecast the 24-hour Pollutant Standards Index (PSI), an air quality measure, to be in the mid to low end of the unhealthy range (101-200). This may even move into the high end of the moderate range (51-100) if winds stay favourable.
At 5am yesterday, the 24-hour PSI hit between 158 and 182 - its highest level since the new PSI was launched in April last year, and the closest it has come to reaching the very unhealthy range (201-300).
Air quality improved throughout the day. At 8pm, the 24-hour PSI was between 124 and 143.
The number of hot spots in Sumatra also fell from 328 on Thursday to 304 yesterday. On Thursday, Indonesia sent more than 1,000 soldiers there to help put out fires.
On the same day, Defence Minister Ng Eng Hen called his counterpart to offer Singapore's aircraft and personnel to seed clouds and aid in firefighting.
Indonesia has accepted this, he said yesterday at the HDB Hub polling centre. He said: "Thankfully, the winds shifted this morning and the haze has come down. But we have to find some way of bringing down the problem, and I'm glad the Indonesian authorities are looking at it."
Despite the unhealthy air quality, many Singaporeans were out and about at East Coast Park, the Botanic Gardens and Bedok Reservoir.
Customer service officer Heddy Fan, 28, said: "There isn't any burning smell today, so it should be safe to come to the Botanic Gardens."
But as a precaution, some opted to wear face masks to the polls. Housewife Vivian Ng, 48, said: "It doesn't look as hazy as before, but I decided to wear one just in case."
Accounts manager Deon Gan, 47, did so as her throat has been itchy and uncomfortable from the haze.
The Singapore Cancer Society said yesterday that it is considering cancelling its Race Against Cancer tomorrow. It will decide by 6pm today whether to proceed with the charity run if the PSI exceeds 100.
CapitaLand will close the external features of its properties, such as outdoor playgrounds, if the PSI crosses 150.
Business at East Coast Lagoon Food Centre has slowed slightly since the haze returned this week, some stallholders said.
Drink stall owner Annie Seet, 56, said the centre, usually packed, has been quiet in the last two days. In the 2013 haze episode, when the 24-hour PSI hit a high of 246, she closed her stall for five days as the haze irritated her eyes and throat.
"I hope it will not be as bad this time," she said.