A global report shows almost all Indian cities did well on the pollution front during last August when benchmarked against the national permissible limit, but most exceeded the WHO guideline limit.
The study, carried out by the Helsinki-based Centre for Research on Energy and Clean Air (CREA), has, however, found ‘spikes’ in the air pollution values of the northern and southern parts of India during the last month despite the ongoing monsoon. Monsoon rains are expected to clean the environment and reduce the ambient pollution level considerably.
PM 2.5 trend
‘India monthly ambient air quality snapshot: August 2026’ finds that in August 2026, 255 out of 258 cities, which had 80% and above days with continuous ambient air quality monitoring stations (CAAQMS) available data, recorded PM2.5 concentrations below India’s National Ambient Air Quality Standards (NAAQS) of 60 µg/m³.
The update adds that 43 cities complied with the World Health Organization (WHO)’s more stringent daily safe guideline PM 2.5 concentration of 15 µg/m³.
PM 2.5 is considered one of the most toxic pollutants, as it can penetrate the respiratory system and impact inner layers of the lungs, often carrying other toxic pollutants alongside, and trigger a range of diseases, including the fatal ones.
“Charkhi Dadri in Haryana was the most polluted city in India in August 2026, followed by Gummidipoondi in Tamil Nadu,” says the report.
NCAP cities under scanner
The monthly average figures show a sharper difference between compliance with India’s and WHO’s permissible limits. “PM2.5 levels in all National Clean Air Programme (NCAP) cities (89 cities with more than 80% of days with data) comply with India’s daily NAAQS for PM2.5, while 75 of 89 NCAP cities exceeded the WHO’s daily guideline,” the report says.
For the 169 non-NCAP cities with over 80% of days with CAAQMS data, 140 cities reported monthly average PM2.5 levels above the WHO daily guideline. Three cities exceeded the daily NAAQS, the Indian standard.
North and south on same page
Charkhi Dadri in Haryana emerged as the most polluted city in India in August 2026, recording a monthly average PM2.5 concentration of 68 µg/m³, exceeding the daily NAAQS limit of 60 µg/m³ for 18 days out of a total of 31 days of observation in the month.
“Gummidipoondi in Tamil Nadu was the second most polluted city in India during August 2026, with a monthly average PM2.5 of 62 µg/m³,” says the report.
Three cities, the two from Haryana and Tamil Nadu and one from Rajasthan, came under the “moderate” category according to Indian limits, even as the remaining cities came under “good” and “satisfactory” categories.
Dombivli was cleanest in August
“Dombivli in Maharashtra was recorded as the cleanest city in India during August 2026, with a monthly average PM2.5 of 5 µg/m³, followed by Kunjemura in Chhattisgarh with a monthly average PM2.5 of 7 µg/m³,” says the report.
All metros, Delhi (35 µg/m³), Kolkata (23 µg/m³), Chennai (20 µg/m³), Bangalore (19 µg/m³) and Mumbai (14 µg/m³), recorded monthly average PM2.5 levels below the daily Indian standard.