Air quality across Singapore remained in the unhealthy range on Saturday (Oct 10) morning, although readings had eased overnight after reaching new highs for this year's haze season on Friday.

At 12pm, the 24-hour Pollutant Standards Index (PSI) reading was 171 in central Singapore, 161 in the west, 154 in the east, 134 in the south and 122 in the north.

The readings were lower than those recorded on Friday when the central region registered a PSI of 192 at 5pm, the highest reading of this year's haze season.

The 1-hour PM2.5 readings were in the elevated band across Singapore at 12pm, ranging from 85 in the south to 119 in the west. The central region recorded 118, while readings in the north and east were 86 and 105 respectively.

The readings had fluctuated overnight but remained below the high band in all five regions.

The National Environment Agency (NEA) had warned on Friday that the 24-hour PSI could exceed 200 and enter the Very Unhealthy range, as smoke haze from southern Sumatra and Kalimantan continued to be blown towards Singapore.

Singapore’s Haze Task Force, comprising 28 government agencies, has been convened and a series of measures are ready to be rolled out should air quality deteriorate further.

If the PSI exceeds 200, N95 masks will be distributed to eligible Singaporeans, while air-conditioned haze shelters at community clubs, as well as selected residents' committee and residents' network centres, will be set up.

Preschools must stop outdoor and strenuous indoor activities when air quality is Very Unhealthy, while outdoor sporting activities may be modified or suspended. Employers have also been advised to limit outdoor work.

Schools may be closed if the next day’s 24-hour PSI is forecast to exceed 300 and enter the Hazardous range.

The haze comes as the Formula 1 Singapore Grand Prix weekend continues at Marina Bay, with the first sprint race in Singapore taking place on Saturday. Organisers have said contingency measures are in place should air quality worsen.