Singapore will close all primary and secondary schools on Friday as worsening pollution causes air quality to deteriorate, the Ministry of Education said Thursday. Smoke from slash-and-burn farming methods in Indonesia has created a choking haze over Singapore for weeks. The three-hour Pollutant Standards Index reading rose to 314, and the 24-hour figure was 223 to 275 on Wednesday night. A reading over 300 indicates “hazardous” air quality, and 201 to 300 is “very unhealthy,” the National Environment Agency said.

Source: Singapore: Air Pollution Closes Schools – The New York Times