By Aakanksha Khajuria

New Delhi, Aug 14 (IANS): The air quality of the national capital improved drastically on Friday following heavy rains that lashed most parts of the city a day ago. People living near the IGI airport enjoyed the best air quality, data showed.

Particulate matter with a diameter of 2.5 and 10 microns, which are too small to be filtered out of the body, plummeted to 18 and 31 micrograms per cubic making the air in the city "good".

The System of Air Quality Weather Forecasting and Research categorizes air quality in the 0-50 range as good, 51-100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor and above 400 as severe.

The overall air quality index is docked at 45 under the 'good' category.

The capital city had witnessed the cleanest air quality of the year with the overall air quality at 42 in March when the nation-wide lockdown was imposed.

The data of 36 air quality monitoring stations on Central Pollution Control Board's website showed that overall air quality near Delhi Technical University (DTU) is still in the 'poor' category at 251 micrograms per cubic.

Out of the total monitoring stations, the air quality at 21 stations, including IGI airport and JNU, is in the 'good' category. Five stations, including the one near ITO, recorded 'satisfactory' air quality, while the station in Delhi's Bawana area recorded 'moderate' air quality. Four station showed no data.

According to the research system introduced by the Ministry of Earth Sciences, incessant rainfall is helping to clean the atmospheric pollutants through the washout process. "Under this favorable condition, AQI forecasted to stay at the lower end of the satisfactory to the good category for the next two days."

On Thursday, heavy rain had inundated low lying areas and threw traffic out of gear at several places. The city had also witnessed heavy rain a night prior to that.

According to the India Meteorological Department, Ayanagar observatory recorded 99.2 mm rainfall, the maximum in the city. Palam, Ridge and Safdarjung stations gauged 93.6 mm, 84.6 mm, and 68 mm precipitation.

The weather bureau has issued a yellow alert for the next five days. Delhi will continue to get heavy rain with lightning and thunderstorm at isolated places due to the moisture incursion from the Arabian Sea and a line of low pressure passing near the city.

Meanwhile, widespread rainfall is also helping air quality to continue in the 'good' category in Pune, Mumbai, and Ahmedabad. The AQI is likely to stay good for the next two days. Pune AQI is the best among all four cities.