Delhi’s AQI is 370, but some platforms show 1,000: Why do readings differ?
Indian Express - Explained · Published 9 November 2026 · Last updated
Delhi’s AQI varied because government and private platforms use different scales, breakpoints and monitoring methods, leading to divergent pollution alerts.
Key points
- CPCB recorded a 24‑hour average AQI of 370 for Delhi on 9 Nov 2026, placing the city in the ‘very poor’ category.
- Private platform AQI.in reported an AQI of 955 (US standard) and 787 (Indian‑standard) for the same period, exceeding the official cap of 500.
- The Supreme Court had allowed only certified green crackers between 6‑7 am and 8‑10 pm on 7‑8 Nov, with a total ban reinstated on 9 Nov, but violations were reported.
- Under GRAP Stage III, active since 6 Nov, Delhi imposed construction curbs, a ban on BS‑III petrol and BS‑IV diesel vehicles, and hybrid school attendance for classes I‑V.
- Experts like atmospheric scientist Gufran Beig note that India’s AQI caps at 500, so values above that do not reflect further pollutant spikes.
- Public‑health specialist Sonu Goel warns that even green crackers emit fine particles (PM2.5) that aggravate respiratory diseases.
- Opposition parties have criticised the government for lax enforcement of the firecracker ban and for not upgrading the AQI methodology.
- The Central Pollution Control Board argues that its AQI scale aligns with the National Air Quality Index framework introduced in 2014 under Swachh Bharat.
- Private monitors cite different breakpoints, averaging periods and sensor locations as reasons for higher readings.
- The Delhi government has urged citizens to limit outdoor activity and wear masks until AQI falls below 300.
Background
- The National Air Quality Index was launched in 2014 as part of the Swachh Bharat campaign, using eight pollutants and capping the index at 500.
- In 2024, atmospheric scientist Gufran Beig explained that AQI breakpoints differ internationally, causing cross‑platform discrepancies.
- The Supreme Court’s 2022 judgment mandated a ban on conventional firecrackers during Diwali, permitting only certified green crackers for limited hours.
- The Graded Response Action Plan (GRAP) was introduced in 2020, defining four stages of emergency measures based on AQI thresholds.
- Delhi’s winter pollution spikes are historically driven by vehicle emissions, construction dust, industrial output and crop‑residue burning.
UPSC relevance, Prelims facts and Mains angle for this issue are in the full SWAदेSH note.
Original report: Indian Express - Explained