Singapore haze remains unhealthy despite showers, with PSI forecast to hit 220

Singapore's haze levels remain unhealthy, despite brief afternoon showers that prevented PM2.5 levels from reaching very high concentrations. The western concentration, which had risen from 111 to 243µg/m3 over 18 hours, peaked at 243µg/m3 before showers likely prevented it from exceeding 251µg/m3, the threshold for very high levels.

Hourly PSI readings showed high concentrations in the southern, central, and western regions, while the eastern and northern areas had elevated levels. The 24-hour Pollutant Standards Index (PSI) ranged from 130 in the north to 199 in the west, placing it in the unhealthy range. Singapore's National Environment Agency attributed the haze to smoke from Kalimantan fires, which had been drifting towards the island under south-easterly winds.

They forecast PSI levels between 150 and 220 for tomorrow, including showers and shifting winds that could reduce smoke from Kalimantan but potentially increase haze from Sumatra. Over the next two days, more showers are expected in Singapore and Kalimantan, with winds weakening and shifting to the southeast or south. This could further decrease smoke from Kalimantan but allow some from Sumatra to drift into Singapore. The agency advised the public to check current PM2.5 levels before engaging in outdoor activities.