Delhi recorded “very poor” air today with an air quality index (AQI) reading of 379 in the 24 hours to midday, the central pollution control board said.

Pollution is expected to worsen tomorrow to “severe” levels above an AQI reading of 400, which poses a risk to healthy people and seriously impacts those with existing diseases.

The restrictions were imposed “considering the highly unfavorable meteorological conditions including calm winds”, said the commission for air quality management (CAQM), which handles air quality in the national capital region.

Its order, among other measures, directed schools to conduct classes in hybrid mode – online and in-person – for students up to Grade 5, and asked the federal government to decide on staggering timings of its office hours.

North India battles intense air pollution every winter as cold air and low temperatures trap vehicular pollutants, construction dust, and smoke from farm fires set off illegally in the adjoining states of Punjab and Haryana.

Delhi recorded its highest pollution during this season last month when AQI readings shot up to 494, prompting the government to close schools and advise offices to allow 50% of employees to work from home.