Air quality in parts of Singapore returns to unhealthy levels as haze persists, with the 24-hour PSI in the central region rising to around 102 at night and late afternoon. Several reports note that the central area re-enters the unhealthy range after previously improving or fluctuating around the moderate level.

Across outlets, the PSI is described as uneven by region: western and central areas move into the unhealthy band first, while the east either reaches unhealthy levels later or dips back to moderate at certain times. One report cites central PSI worsening to 128 in the morning, alongside higher readings in the east and west, while another notes that by late on the same day/nearby days, readings across Singapore shift back to moderate as the central PSI falls to the high-90s. Separate coverage also places the changes over specific dates and times, showing the pattern of the haze repeatedly pushing PSI up and then easing back.