Rain helps Delhi see best air quality in 4 years, even as few areas show concern

Delhi recorded 87.9mm of rainfall between October 17 and 18 – the fourth highest in a day ever in October, and the highest since 1956, when the national capital received 111mm rain, as per IMD data.

Owing to record rainfall in Delhi in October, the national capital has witnessed its best air quality in a single month in four years, news agency PTI reported on Sunday.

Notably, an AQI from 201 and 300 is termed as “poor”, while 301 and 400 as “very poor”, and 401 and 500 as “severe”. (Biplov Bhuyan/HT PHOTO)

As reported by Hindustan Times earlier in the day, the city is yet to record a “very poor” air quality index this month. However, forecasters from the India Meteorological Department (IMD) cautioned against the air quality worsening and likely entering the “very poor” category from Sunday onwards. According to data available on the CPCB website, more than four stations of the government agency in the national capital are already experiencing “very poor” air quality. The AQI in Anand Vihar at 9pm on Sunday was 360, in Chandni Chowk at 340, in Jahangirpuri at 377, and in NSIT Dwarka at 338, among other stations.

“Wind speeds might slow down from Sunday and this would adversely impact the city’s air quality,” a senior IMD official said.

Delhi recorded 87.9mm of rainfall between October 17 and 18 – the fourth highest in a day ever in October, and the highest since 1956, when the national capital received 111mm rain, as per IMD data.

The PTI report also mentioned that stubble burning and its share in Delhi’s PM 2.5 pollution remained low owing to heavy rainfall. Typically, air quality in the city starting November commences to deteriorate supremely, systematically reaching to “severe” category every year, due to stubble burning in neighbouring states of Haryana, Punjab and Uttar Pradesh.

In October, Delhi has recorded three “satisfactory” AQI days as against none in 2020, four in 2019, and none again in 2018. Moreover, the city witnessed as many as 19 “moderate” AQI days as opposed to six each in 2020, 2019 and 2018. Also, the eight “poor” AQI days the national capital saw this month was the lowest in October in three years.

Notably, an AQI from zero and 50 is termed as “good”, 51 and 100 as “satisfactory”, 101 and 200 as “moderate”, 201 and 300 as “poor”, 301 and 400 as “very poor”, and 401 and 500 as “severe”.