The cold continued to grip Delhi on Tuesday as the day recorded the lowest temperature in 22 years.

Emission of firecrackers and stubble burning has contributed to the increase in poor air quality. It is expected that the air quality will get worse in coming days.

After four consecutive days of "severe" air pollution, Delhi's air quality improved to "very poor" and according to the weatherman, it is likely to remain in the same zone for the next three days, with dense fog engulfing the city.

It was a cold foggy Tuesday morning in the national capital with visibility dropping to 50 metres affecting flight schedule and causing train cancellations.

The national capital woke up to a cold morning on Sunday with mist and shallow fog with the minimum temperature settling at 7.2 degreed Celsius, a notch below the season's average, while the air quality remained in the 'poor' category, the weather office said.

Life expectancy in the national capital has declined by over 10 years with a trend of hosting bad air, specially during the crop burning season. In last two decades, 2016 was the year with worst air quality measured.

The capital's citizens on Thursday struggled to breathe better air as pollution levels spiked across the city after Diwali, touching the "very poor" category.

Back is the season when Delhi's air quality turns hazardous for its residents, making it worse is the Diwali festival when people burst thousands of firecrackers only to decline fresh air quantity.

The air quality in Delhi-NCR worsened to the "severe" level on Tuesday, as an overnight spike in pollution covered the city in a smoky haze.

The air quality in the capital deteriorated to an alarming level on a hazy Sunday, forcing Sri Lankan cricketers to cover their faces with anti-pollution masks in a Test match at Delhi's Feroz Shah Kotla stadium.