Delhi's air quality plunged to 'very poor', with a thick layer of haze blanketing the national capital, early on Tuesday.

At 9 am, Delhi's Air Quality Index (AQI) was recorded at 392, compared to a reading of 281 at 9 am on Monday, according to Central Pollution Control Board (CPCB) data.

An AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.

The CPCB data also showed that 17 of the national capital's 39 monitoring stations recorded air quality in the 'severe' category.

An AQI of 400 or higher -- classified as 'severe' -- poses significant health risks to both healthy individuals and those with pre-existing medical conditions.

Meanwhile, the city's minimum temperature settled 0.6 notches above normal at 11.9 degrees Celsius, the India Meteorological Department said.

It has forecast mainly clear skies during the day, with the maximum temperature expected to hover around 27 degrees Celsius.

At 8:30 am, the humidity level was at 80 per cent.

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