Air quality in two regions of Singapore crossed into the unhealthy range as of 9pm today (Sep 4). Both the central and east regions recorded a 24-hour PSI of over 100 for the first time since 2023. The National Environment Agency will issue daily haze updates. It said transboundary haze may continue to affect Singapore in the coming days as dry conditions are forecast. The 24-hour PSI is forecast to be as high as within the unhealthy range. Natalie Ong reports.