Hanoi: Schools may suspend classes if air pollution is severe

Units and schools in Hanoi must limit outdoor activities for students during hours and days when air quality is at "bad" level or higher. In case of serious air pollution (VN-AQI ≥ 301), units and schools must proactively suspend or adjust working and studying hours accordingly.

This is a proposal from the Department of Education and Training. Hanoi is stated in Document No. 5095/SGDĐT-CTTTHSSV dated December 3, 2025 sent to People's Committees of wards and communes; affiliated units and schools on strengthening urgent measures to control air pollution in the city.

Schools and units in Hanoi must limit outdoor activities for students during hours and days when air quality is at "bad" level or higher. Illustration photo: dantri.com.vn

Accordingly, in order to ensure the health of students, staff, teachers and employees of units and schools, the Hanoi Department of Education and Training requests the People's Committees of wards, communes, units and schools to strictly implement the directive of the City People's Committee on strengthening urgent measures to control air pollution in the area. The Department requests units and schools to proactively adjust their study schedules and outdoor activities accordingly.

Units and schools need to regularly update information on air quality and monitor the VN-AQI index at monitoring stations in the city at the website: http://moitruongthudo.vn.

As every year, the end of November to the beginning of December is the peak of the “air pollution season in Hanoi” (lasting from October of the previous year to April of the following year). Fine dust suspended in the lower atmosphere cannot diffuse, causing air pollution.

At this time, Hanoi is cold and dry, daytime temperatures fluctuate between 19-24 degrees Celsius, at night and early morning they drop to 12-14 degrees Celsius. Environmental experts say the large temperature difference between day and night combined with the phenomenon of temperature inversion (temperature inversion) makes it difficult for PM2.5 fine dust to diffuse.

Source: https://baolangson.vn/ha-noi-cac-truong-co-the-tam-dung-viec-hoc-nu-khong-khi-o-nhiem-nghiem-trong-5066928.html