Levels of particulate matter 2.5 micrometres or less in diameter (PM2.5) have reached the "unhealthy" red zone throughout the North and the upper Northeast, with the highest level exceeding the safe threshold of 50 microgrammes per cubic metre (µg/m³) by over eight times, as people in Chiang Mai have been urged to stay indoors and work from home at this time.
- North -
