Why Delhi’s air turned ‘poor’ despite monsoon rains
On Monday, the city’s AQI touched 246. This comes less than a week after Delhi recorded its first ‘Good’ air day of the year. The reason? A dust storm in West Asia
Barely days after successive monsoon showers gave Delhi its cleanest air in nearly three years, the national capital saw its pollution levels spiking — owing to a dust storm from West Asia.
On Monday, the average Air Quality Index (AQI) was recorded in the ‘Poor’ category (AQI 246) for the second day in a row. On Sunday, the AQI had climbed to 261, the first ‘Poor’ air day of this month.
However, the Commission for Air Quality Management in NCR noted on Monday, “… the transboundary dust storm is subsiding and further improvement in air quality is expected. In view of the improving trend, the Sub-Committee decided not to invoke Graded Response Action Plan (GRAP) Stage-I.”
From ‘Good’ to ‘Poor’ in three days
The sharp deterioration comes less than a week after Delhi recorded its first ‘Good’ air day of the year.
On July 9, the city’s daily average AQI had dropped to 48, the lowest recorded this year and the cleanest air Delhi had witnessed since September 10, 2023. Back-to-back spells of monsoon rain had washed pollutants out of the atmosphere, keeping air quality in the ‘Good’ and ‘Satisfactory’ categories for several days.
The latest spike has effectively wiped out those gains, with the AQI jumping more than 200 points within three days.
According to the Commission for Air Quality Management (CAQM), the sudden deterioration is being driven by a large-scale transboundary dust event rather than local pollution sources.
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“The decline in air quality is attributed to long-range transboundary mineral dust transport, with a storm originating near Afghanistan, Iran and Pakistan moving towards north western India including Delhi, resulting in elevated atmospheric PM10 concentrations,” the commission said after a meeting of the GRAP Sub-Committee on Sunday.
The commission added that strong winds over the Indo-Gangetic Plain were carrying mineral dust into Delhi-NCR, leading to a sharp increase in Particulate Matter (PM) 10 levels across monitoring stations.
Dr Shashi Kant, senior scientist at the India Meteorological Department (IMD), said satellite imagery indicates that the dust-laiden wind is arising from South Pakistan and adjoining areas, resulting in transboundary dust transport into India.
No GRAP Stage-I despite AQI crossing 200
Despite the daily average AQI breaching the 200-mark, the CAQM decided against invoking Stage I of GRAP. “Delhi’s air quality is in the ‘Poor’ category as of today and likely to remain in this range. AQI is expected to improve in a couple of days as the transboundary dust spell subsides,” the commission had said during the day.
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However, the Delhi Pollution Control Committee (DPCC) and State Pollution Control Boards in NCR were directed to intensify dust-control measures on the ground. “The Sub-Committee shall be keeping a close watch on the air quality scenario and review the situation from time to time for further appropriate decisions, depending upon the air quality and forecast made by IMD/IITM,” the statement added.
PM 10 dominant pollutant
The current pollution episode is markedly different from the winter smog that is typically driven by locally generated emissions and secondary particulate formation.
Data from the Central Pollution Control Board’s monitoring network shows PM 10 has emerged as the dominant pollutant across most stations as coarse mineral dust suspended by strong winds replaced the rain-cleansed atmosphere.
Sophiya Mathew is a Correspondent at The Indian Express, based in New Delhi. She joined the Delhi bureau in 2024, and has specialization in Integrated Multimedia Journalism from the Asian College of Journalism (ACJ), Chennai.
Professional Background
Core Beats: Her reporting is primarily focused on the Environment and Education.
Specialization: She has gained recognition for her ground-level reporting on the Yamuna floodplains and the socio-economic challenges faced by those living on its banks. She also focuses on the disparities in Delhi's education system, ranging from elite private schools to government institutions and refugee education.
Recent Notable Articles (December 2025)
Her recent work has been heavily centered on Delhi's severe winter pollution crisis and the government's regulatory responses:
1. The Air Pollution Crisis
"A tale of two cities: Delhi govt schools choke in bad air, private classrooms set up air filters" (Dec 20, 2025): A high-impact feature contrasting the "Clean Air Bubbles" in elite schools with the reality of government school students who are exposed to an equivalent of 17 cigarettes a day due to outdoor exposure.
"Delhi sees season's worst air day, second worst December AQI in nearly a decade" (Dec 15, 2025): An analytical report on the meteorological patterns trapping pollutants in the NCR.
"Delhi bans non-BS VI vehicles from outside: Why curbing vehicular pollution is key" (Dec 17, 2025): Explaining the science behind targeting specific vehicle vintages to lower particulate matter.
2. Enforcement & Regulations
"No fuel at pumps in Delhi without valid PUC certificate from December 18" (Dec 17, 2025): Breaking the news on the environment ministry's strict "No PUC, No Fuel" policy.
3. Education Policy
"Law to regulate school fee in Delhi risks becoming procedural, say parents" (Dec 13, 2025): Investigating the loopholes in the new Delhi School Education (Transparency in Fixation and Regulation of Fees) Bill, 2025.
"Monsoon Session: Private school fee regulation Bill cleared after four-hour debate" (Aug 9, 2025): Covering the legislative passage of the controversial fee hike regulation.
Signature Style
Sophiya is known for her observational depth. Her reporting often includes vivid details from school corridors, hospital waitlists, or the banks of the Yamuna to illustrate how policy failures affect the city's most vulnerable residents. She is a frequent expert guest on the 3 Things podcast, where she explains the complexities of Delhi’s environmental laws.
X (Twitter): @SophiyaMathew1 ... Read More
