Delhi’s Air Quality Deteriorates to ‘Very Poor’ as Wind Stagnation Chokes Pollution Dispersion
The national capital woke up to a blanket of haze on Saturday morning as pollution levels surged, pushing Delhi’s Air Quality Index (AQI) to 386, marking a sharp rise from 303 the previous day. With weak northwesterly winds and low ventilation rates, the smog trapped over the city has led to yet another spell of suffocating air — one that shows little sign of immediate relief.
Slow Wind Speeds Hamper Dispersion of Pollutants
According to the Air Quality Early Warning System (AQEWS), wind speeds in the national capital region fell below 8 kmph during the evening and night hours. This drastic slowdown, combined with a ventilation index below 6,000 m²/s, created an environment highly unfavorable for pollutant dispersion. When winds weaken and the air stagnates, suspended particulate matter such as PM2.5 and PM10 remain concentrated close to the ground, worsening breathing conditions across the city.
AQI Enters ‘Very Poor’ Category, Some Zones Hit ‘Severe’ Levels
Out of Delhi’s network of monitoring stations, seventeen reported ‘severe’ air quality with AQI readings above 400. Wazirpur emerged as the worst-hit locality, recording an alarming AQI of 439, while twenty other stations showed ‘very poor’ air quality above 300. Experts caution that prolonged exposure to such conditions can trigger respiratory distress, particularly among vulnerable groups including children, the elderly, and individuals with pre-existing heart or lung ailments.
Understanding the AQI Scale
India’s air quality is assessed on a scale of 0 to 500, where 0–50 is considered ‘good’, 51–100 ‘satisfactory’, 101–200 ‘moderate’, 201–300 ‘poor’, 301–400 ‘very poor’, and 401–500 ‘severe’. The current reading of 386 places Delhi’s air in the ‘very poor’ category, signaling that pollutants are now concentrated at levels hazardous for prolonged outdoor exposure.
Weather Conditions Offer Little Respite
Meteorological data from the India Meteorological Department (IMD) indicated a minimum temperature of 16.8°C, about 1.5°C above the seasonal average, with morning humidity hovering around 79%. The combination of mild temperatures, high moisture content, and sluggish air movement has effectively capped pollutants close to the surface. The IMD forecasts mainly clear skies during the day and shallow fog at night, with the maximum temperature likely to touch 31°C — conditions that may prolong poor visibility and worsen respiratory discomfort.
Experts Warn of Continued Smog till November 4
Environmental scientists have expressed concern that Delhi’s air quality will remain in the ‘very poor’ range until November 4, unless wind speeds pick up or there is a change in atmospheric conditions. The stagnant weather pattern is also being compounded by ongoing emissions from vehicular traffic, construction dust, and post-harvest stubble burning in neighboring states.
The Broader Picture: Seasonal Smog Returns to Delhi-NCR
Every year, as winter sets in, Delhi faces the challenge of air stagnation and particulate buildup. Reduced wind flow and lower temperatures trap pollutants near the ground, creating a toxic layer of haze. While authorities continue to enforce measures such as construction bans, traffic restrictions, and smog towers, experts emphasize that long-term solutions require region-wide coordination, stricter emission controls, and a shift toward cleaner fuel and transport systems.
