After rain, winds, Delhi logs best air day since October

On Tuesday, Delhi’s 24-hour average Air Quality Index (AQI) reading was 75 (satisfactory) according to CPCB’s daily bulletin, a notable improvement from Monday’s reading of 154 (moderate)

Strong surface winds and rain over the past four days in the Capital led to Delhi’s air quality improving from the “moderate” to the “satisfactory” for the first time in nearly six months, data from the Central Pollution Control Board (CPCB) showed on Tuesday.

Mercury in the Capital had clocked 25.3°C on Saturday, when the unusually pleasant spell of cool winds and rain began. (Raj K Raj/ HT Photo)

On Tuesday, Delhi’s 24-hour average Air Quality Index (AQI) reading was 75 (satisfactory) according to CPCB’s daily bulletin, a notable improvement from Monday’s reading of 154 (moderate). The last time Delhi’s air was “satisfactory” was on October 11, 2022, when the AQI reading was 66.

India Meteorological Department (IMD) on Tuesday said while no rain was likely on Wednesday or Thursday, it has issued a yellow alert--to warn the public of a weather phenomenon --for Friday, forecasting light rain and gusty winds of 30-40kmph in the Capital.

Before Tuesday, the lowest AQI reading this month was 119 (moderate) on March 9. Last month, the lowest AQI reading was 132 (moderate) on February 14. An AQI reading between zero and 50 is considered “good”, 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.

Delhi also received 10.4mm of rain between 8.30am on Monday and 8.30am on Tuesday. With this, Delhi has now received 16.1mm of rain in March, a few notches below the normal monthly mark of 17.4mm, officials said.

“While this current western disturbance is departing, cloudiness will still prevail for another 24 hours. We expect the maximum to rise slightly on Thursday, but Friday will see the fresh impact of the next western disturbance, which will once again bring light rain and strong winds,” said Kuldeep Srivastava, scientist at IMD.

During Tuesday’s rain spell, Srivastava says Palam recorded the highest wind speed of 46kmph, and Safdarjung recorded a speed of 32kmph. Strong winds and rain both assisted in dispersing the pollutants, he said.

However, a forecast by the Early Warning System (EWS) for Delhi, used by the Commission for Air Quality Management (CAQM) in NCR, shows the AQI is expected to return to the “moderate” range by Wednesday.

“Delhi’s air quality is likely to move to the ‘moderate’ category from Wednesday. The outlook for the subsequent six days shows the air quality is likely to remain in the ‘moderate’ category.” EWS said on Tuesday.

Meanwhile, Safdarjung, which is representational of Delhi’s weather, recorded a maximum temperature of 25.8 degrees Celsius (°C) on Tuesday--five degrees below normal-- a dip from the 27.1°C recorded on Monday and 28°C recorded on Sunday. Mercury in the Capital had clocked 25.3°C on Saturday, when the unusually pleasant spell of cool winds and rain began.

Delhi’s minimum temperature on Tuesday was meanwhile recorded at 14.1°C – two notches below normal-- also a dip from 17.1°C recorded on Monday.