The skies were slightly hazier than usual on Monday. The three-hour PSI or Pollutant Standards Index, a measure of air quality, began creeping up on Sunday afternoon, and was 50 at lunchtime on Monday. At 5pm, the three-hour PSI was 41, while the 24-hour PSI was 44 to 49. A PSI of 0 to 50 remains in the 'good' range, while that between 51 and 100 is 'moderate'. More details from NEA will come soon on the cause of the increase in the PSI. Did you notice the hazier conditions? Did it affect you in any way? Please leave your comments below.