New Delhi: Delhi’s air quality deteriorated to ‘severe’ on Sunday, with the 24-hour average Air Quality Index (AQI) recorded at 409, officials confirmed.

The national capital’s Air Quality Index (AQI) had been in the ‘very poor’ category on Saturday, with a reading of 370. 

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’.

According to the air quality scale, an AQI between 401 and 500 is classified as ‘severe,’ indicating a high level of pollution that can pose significant health risks.

On Sunday, the city also saw weather conditions that contributed to the poor air quality. 

The maximum temperature was recorded at 24.1 degrees Celsius, three notches above normal, while the minimum temperature settled at 7.3 degrees Celsius, one notch below normal, as per the India Meteorological Department (IMD).

Fog was reported in the morning, with humidity levels ranging between 68% and 97%, further reducing visibility and exacerbating the pollution.

The IMD has predicted cloudy skies and light rain for Monday, with temperatures expected to range between 20 and 7 degrees Celsius.

In the context of persistent air pollution, Delhi has frequently experienced severe air quality conditions during the winter months, largely due to factors such as vehicular emissions, crop burning in surrounding states, and weather patterns that trap pollutants near the ground.