Delhi Air Quality Reaches Very Poor Levels as Diwali Approaches

Delhi's air quality remained in the very poor category for a fifth consecutive day on Friday, with the 24-hour average Air Quality Index reaching 387 by early morning, according to the Central Pollution Control Board.

Twenty-eight of the city's active monitoring stations recorded severe readings above 400. Rohini reported the highest figure at 473, followed by Punjabi Bagh at 464 and RK Puram at 441. Other stations in Alipur, Sonia Vihar, and North Campus also exceeded 420. The previous day's 4 p.m. bulletin had shown 369, and the morning reading marked a clear rise overnight.

Low wind speeds near the ground allowed pollution to accumulate. A layer of warmer air aloft limited vertical mixing, trapping emissions close to the surface. Higher-altitude winds carried additional particles from the northwest, where farm fires continued in Punjab and Haryana. Satellite observations counted 226 such fires on Thursday.

Stubble burning contributed an estimated 15 to 19 percent of Delhi's PM2.5 on Thursday, with the share expected to rise further on Friday. Vehicle emissions, construction dust, and industrial sources remain the dominant local contributors. The combination has produced thick haze across the National Capital Region, reducing visibility on major roads.

The Air Quality Early Warning System has forecast that levels will enter the severe category from Friday through the weekend. Diwali falls in the coming days, and past years have shown sharp spikes from firecrackers on top of existing pollution. Health officials advise residents to limit outdoor activity, especially children, the elderly, and people with respiratory conditions.

The pattern matches previous years in which post-monsoon agricultural burning coincides with cooler weather and weaker winds. Last week's brief improvement, when the AQI fell into the satisfactory range, has reversed. Readings have climbed steadily from 324 on Monday to the current levels.

NCR cities face similar conditions. Gurugram and Noida have also recorded elevated PM2.5 concentrations. Authorities have not yet announced additional emergency measures beyond existing construction and vehicle restrictions in the severe category, but further steps remain possible if readings stay high through the festival period.

Residents have reported reduced outdoor activity and increased use of air purifiers. Hospitals typically see higher admissions for breathing difficulties during these episodes. The CPCB classifies 301–400 as very poor and 401–500 as severe, categories that carry documented health risks for the general population.

Meteorological conditions are expected to remain unfavorable for dispersion over the next several days. Without stronger winds or rain, the combination of local emissions and transported smoke is likely to keep the AQI elevated. The timing relative to Diwali adds a predictable source of additional particles that have historically pushed readings higher.