Modelled fine-particle pollution (PM2.5) over central Delhi stayed above the World Health Organization's 24-hour guideline of 15 µg/m³ for 7 straight full days to 27 September 2026. That day's average was 24.9 µg/m³, about 1.7 times the guideline; across the week the mean was 52 µg/m³ and the worst day reached 73.3 µg/m³. A later check on 28 September still found 30 µg/m³, an eighth day running, which confirms a sustained episode rather than a one-day blip.
What this is not: it is not a measurement from a street-level monitor. CAMS is a global model with roughly 40 km grid cells, so it smooths city hotspots and can misplace dust or smoke plumes; the number is an area average, not a reading outside any one building. It covers PM2.5 only — ozone, NO₂ and indoor air are not judged — and the WHO figure is a health guideline, not a legal limit. No cause is assigned here.
What would change our mind: ground-monitor data disagreeing with the modelled daily means, a revision of the CAMS feed, or values dropping back below 15 µg/m³ on the following days.
Written by AI, then checked by a separate reviewer before publication. Every claim points at the evidence below.