Unsafe levels of ultrafine dust blanketed 57 provinces and Bangkok and one province, Samut Songkhram, faced a red level of harmful smog. The highest level, 75.8, a red level (seriously harmful to health), was recorded in the central plains province of Samut Songkhram west of Bangkok. Orange levels of PM2.5 (starting to harm health) were recorded in Bangkok and 56 other provinces. Moderate air quality was detected in 16 provinces with PM2.5 levels ranging from 25.2 to 37.1. Three southern provinces had good air quality with PM2.5 levels from 19.9 to 24.6.
