unhealthy Pollutant Standards Index (PSI) readings<\/span><\/a> daily since Oct 5 \u2013 making this 12-day period the longest continuous stretch of poor air quality the country has had to endure since the 2015 haze crisis.<\/p>\nThat year, Singapore experienced a 14-day stretch of bad air between Sept 23 and Oct 7, The Straits Times checks on historical 24-hour PSI readings on government data portal Singstat showed.<\/p>\n
In comparison, during the haze episodes in 2019 and 2023, Singapore experienced shorter stretches of unhealthy air, with each lasting a couple of days.<\/p>\n
A day is considered to have unhealthy air quality when the PSI reading at any point in the day exceeds 100 in any part of Singapore.\u00a0<\/p>\n
Singapore\u2019s PSI has five bands \u2013 good (0-50), moderate (51-100), unhealthy (101-200), very unhealthy (201-300) and hazardous (>300).<\/p>\n