New Delhi: After three days of apocalyptic haze and smog turned Delhi into a gas chamber, the Capital breathed easier on Tuesday as the air quality slightly improved from ‘severe’ to ‘very poor’ category.

Scientists at the India Meteorological Department (IMD) said the pollutants from the air were cleared because of the increase in wind speed on Monday. With winds gusting up to 20 kilometres per hour dispersing pollutants faster, the visibility level improved to 2,000 metres.

The India Meteorological Department said Cyclone Maha and a western disturbance will cause rainfall in parts of the northern plains, covering Rajasthan, Punjab, Haryana, western Uttar Pradesh and Delhi-NCR, on Wednesday and Thursday which is likely to improve the situation.

The Delhi government also shared data that showed a drastic improvement in PM10 and PM2.5 levels in the city.

According to the data, the levels of PM2.5 — tiny particulate matter less than 2.5 microns in diameter that can enter the lungs and even the bloodstream, reduced from 562 micrograms per cubic metre at 6am to 94 micrograms per cubic meter at 6 pm.

PM10 levels reduced from 710 micrograms per cubic meter at 6 am to 216 micrograms per cubic meter at 6 pm.

Kuldeep Srivastava, a senior scientist at the IMD, said, "The two main reasons for the improvement in air quality are increased wind speed and no cloud cover. The situation will improve on Tuesday with wind speed increasing further."

Mahesh Palawat of Skymet Weather, a private forecaster, said rainfall is likely in Delhi and neighbouring areas on Wednesday and Thursday under the influence of Cyclone Maha.

"A western disturbance will also increase wind speed... Strong easterly winds due to Cyclone Bulbul will reduce the impact of smoke from stubble burning in (Haryana and Punjab)," he said.

The Ministry of Earth Sciences' air quality monitor, SAFAR, said, "High surface and boundary layer winds are expected on Tuesday also. A fresh western disturbance, scattered rainfall and change in wind direction are likely to positively influence the AQI in the region."

In the National Capital Region (NCR), Noida (391), Ghaziabad (392) and Greater Noida (392), Gurgaon (355), Faridabad (378), also recorded improvement in air quality.

An AQI between 0-50 is considered ''good'', 51-100 ''satisfactory'', 101-200 ''moderate'', 201-300 ''poor'', 301-400 ''very poor'' and 401-500 ''severe''. Above 500 falls in the ''severe plus'' category.

Terming the pollution in national capital as 'atrocious', the Supreme Court on Monday said that people are not safe even inside their house. The top court ordered an immediate and complete stop to stubble burning by farmers in Punjab, Haryana and Uttar Pradesh, blamed for 46 per cent of the pollution.

The court also noted that people in the NCR were losing "precious years of their lives" and cannot be "left to die" due to the current pollution situation which should not be there in a civilised country, adding it had no sympathy for farmers indulging in burning of stubble as they are putting lives of others at risk.