Good and moderate air quality according to share of days Singapore 2007-2021
In 2021, the share of days in the year with good and moderate air quality in Singapore stood at 99.5 percent, an increase of three percentage points compare to the previous year. During this year, there were two days where PSI entered the Unhealthy range due to elevated Ozone levels. Singapore experienced a full-year of good and moderate air quality (in terms of PSI) in the years 2007, 2008 and 2018. Air quality in 2013 and 2015 was affected by transboundary smoke haze from land and forest fires. The lowest share of good and moderate air quality was in 2015 where it was recorded at 87.5 percent.
