Overview
- Official Central Pollution Control Board data on Thursday showed Delhi's citywide AQI in the low–mid 300s with dozens of stations above 300 and several sites reporting 'severe' readings over 400.
- Government monitors use reference-grade BAM/TEOM analysers with heated inlets and report 24-hour averages that are capped at 500 while many private apps show near-real-time optical-sensor spikes that can read much higher in humid or foggy conditions.
- Independent analyses from IITM's Decision Support System and CSE attribute a large share of recent PM2.5 to local transport plus variable transported emissions from farm fires, with CSE reporting a pre-Diwali PM2.5 baseline far higher than last year.
- The Commission for Air Quality Management has kept GRAP emergency restrictions in force across Delhi-NCR and authorities say some government analysers flagged or discarded out-of-range readings when raw particulate levels exceeded instrument calibration limits.
- The poor air is already harming residents' health through coughing and low visibility and it raises the risk of more days of hazardous air if weather forecasts show continued calm winds and persistent sources of smoke.