High temperatures help make February 2nd cleanest in Delhi since 2016

NEW DELHI: Aided by the early exit of winter, Delhi this year saw its second cleanest month of February in terms of air quality since the Central Pollution Control Board started measuring AQI from April 2015. The average AQI during the month was 237, the lowest after 225 in February last year.
Although the month did not see any “good” or “satisfactory” air days, strong winds and high temperatures on most days helped in better dispersion of pollutants, experts said. The month saw five “very poor”, 13 “poor” and 10 “moderate” air days. There were just four “very poor” air days in February last year.
The average AQI of February was highest in 2016 at 291. It was 267 in 2017, 243 in 2018, 242 in 2019, 241 in 2020 and 288 in 2021.
Explaining the meteorological factors that helped keep the AQI relatively low this February, a met official said, “The first half of February was windy. The strong winds aided in dispersion of pollutants. The second half of the month saw high temperatures on most days which helped in better ventilation. The temperatures were four to nine degrees above normal on most days.”
Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment (CSE), said, “The overall pollution levels are expected to come down in February compared to the peak and average levels in winter. This has also been the warmest February in the past 17 years. The level of pollution concentration is also lesser due to changing meteorology.”
She added, “This is the time to ramp up action to ensure sustained improvement and reduce dependence on emergency action during winter. Focus on reducing emissions from all key sectors.”
According to CPCB, January and February 2023 saw 47 days when the AQI was between 301 and 500 (in the “very poor” to “severe” range). Last year, 44 such days were recorded during the same period.
An AQI reading of 50 or below is classified as “good”, readings between 51 and 100 on the index fall in the “satisfactory” category. Readings between 101 and 200 are considered “moderate”. “Poor” air ranges from 201 to 300, “very poor” from 301 to 400 and “severe” from 401 to 500.