On Friday, levels of particulates 2.5 micrometers or less in diameter, the most harmful to human health, peaked at 845, according to the USA embassy website that monitors air quality independently.
The overall air quality index (AQI) Thursday was recorded in the "severe plus emergency" category at 642, according to Centre-run System of Air Quality and Weather Forecasting and Research (SAFAR) data.
Delhi's air quality typically worsens in winter, as clouds of smoke from farmers' fires billow into the city and mix with industrial and traffic emissions to form a noxious cocktail.
In 2016, Diwali festivities raised pollution levels to their highest in almost two decades - forcing the closure of schools and other emergency measures.
Air quality took a hit this Diwali despite the time restriction on bursting firecrackers, which was flouted in several parts of the city. Patiala, Khanna and Rupnagar, had recorded 150, 186, and 83 AQI on Diwali day respectively which had gone upto, 264, 208 and 146 on Diwali night. Delhi's air quality showed "significant" improvement as compared to Thursday when it went off the charts to the "severe plus emergency" category. The Central Pollution Control Board's (CPCB) air quality forecast suggests that air quality will continue at "very poor" levels for the next three days across NCR. These indices measure the concentration of tiny poisonous particulate matter.
The court also ruled that firecrackers could only be set off between 8:00 pm and 10:00 pm, but their bangs were still reverberating around city neighbourhoods well after midnight. There was 36 per cent and 44 per cent reduction in PM10 and PM2.5 levels respectively than the previous year which is a very encouraging trend.
The overall AQI of the city was 11 times the permissable limit. The government has said that the authorities are taking measures to curb the air pollution levels including banning trucks from entering the national capital till December.
The national capital woke up to a yet another smoggy morning on Friday with the air quality in the "severe" category.
The court had asked police to ensure that banned fireworks were not sold and said in case of any violation the commanding officer of the police station concerned would be held personally liable and it would amount to committing contempt of the court.
But despite the apex court order, there were reports of its violation from many areas long after 10 pm.