Air quality in central Singapore has deteriorated, returning to unhealthy levels as haze conditions persist. The 24-hour Pollutant Standards Index (PSI) reading in central Singapore reached 102 at 11pm, indicating a move into the unhealthy range. This decline suggests a worsening of the haze situation affecting the region. Authorities have not yet issued specific advisories, but residents, particularly those with respiratory conditions, are advised to take precautions. The situation is being closely monitored for further changes in air quality across Singapore. This latest development raises concerns about the ongoing impact of transboundary haze on public health.