The air quality in Delhi was very close to the “severe” category on Tuesday morning, with the Central Pollution Control Board recording 378 on its index at 8 am. This was slightly better than Monday afternoon, when the air quality deteriorated to 390.

An air quality index higher than 400 is classified as “severe”.

Ghaziabad and Agra had worse air quality on Monday, in the “severe” category. Ghaziabad, a district of Uttar Pradesh that borders Delhi, had a 24-hour average air quality index of 467 on Monday evening.

On Sunday, the air pollution in Delhi had worsened and forced interruptions during an international cricket match in the city. The average index value on Sunday was 351, significantly better than Monday’s 390.

This decline in air quality could be a result of a fall in temperatures and higher moisture in the air because of Cyclone Ockhi in the south, The Times of India reported, quoting experts.

On Monday, the concentration of the particulate matter of diameter less than 2.5 microns – PM2.5 – was 276 micrograms per cubic metre at 3 pm. A level of below 60 is considered safe.

According to a forecast by aqicn.org, the air quality will improve later in the week.