Analysts expect around 600 to 700 units to be sold in August.
Tembusu in the suburbs in Kovan was one of the few projects launched in August - traditionally a lull period because of the Hungry Ghost Festival.
Private homes along the coastline of Singapore. -- Photo AFP
Another dampener to the property market was the Total Debt Servicing Ratio (TDSR) framework, which was imposed in late June.
The TDSR limits how much property buyers can borrow to buy homes.
Meanwhile, market watchers expect developers to change their sales strategy.
Christine Li, research head at OrangeTee, said: "They are looking at ways to help buyers to tide over this period, especially genuine upgraders who would need to offload their existing properties before they qualify for a bigger loan.
"So going forward, we might see developers coming up with some kind of measures to help these people tide over the construction period of their new homes."
In July, 481 new private homes were sold, down 73 per cent from June before the loan curbs came into place.
August's forecast is just about half the 1,421 new condo units sold in August last year.
Some market watchers said the cooler home market activity may affect prices.
Chua Yang Liang, research head of Southeast Asia and Singapore at Jones Lang LaSalle, said: "I think there will probably be a very marginal increase. In fact, we see some downside in terms of overall, especially in the high-end market. There is some downside risk because of the weaker transaction."
But like the other rounds of cooling measures, some expect property buyers to return to the market in September, particularly with new launches piquing interest.
Alan Cheong, research head at Savills Singapore, said: "The URA's (Urban Redevelopment Authority) average prices for September will probably still be higher than in August because in August, you still see some projects that were sold below S$1,000 psf (per square foot).
"But today, on average, a mass market suburb site on GLS (Government Land Sales) is pushing to S$1,200 to S$1,600 psf. So index wise, you would still have an upward momentum up till the end of the fourth quarter."
According to URA, prices of private homes in the city dipped 0.2 per cent in the second quarter of this year, prices of homes in the city fringes gained 0.2 per cent, while that of suburban homes gained 3.8 per cent.
URA will release the new home sales data for August on Monday.