The National Capital Region (NCR) continued to struggle under a thick blanket of pollution and fog on Friday, December 20, 2025, with air quality deteriorating in several areas. While Delhi's average air quality index (AQI) stayed in the 'Very Poor' category, neighbouring Noida slipped into the 'Severe' zone, signalling a worsening environmental crisis.
Air Quality Worsens Across NCR
Data from the Central Pollution Control Board (CPCB) painted a grim picture for the day. Delhi recorded an average AQI of 374, a marginal increase from Thursday's 373, firmly placing it in the 'Very Poor' bracket. The situation was more alarming in the satellite cities. Noida's AQI hit 410, pushing it into the 'Severe' category. Gurgaon also saw a significant dip, with its AQI worsening to 322 (Very Poor) from 276 (Poor) the previous day.
Within the capital, the pollution was not uniformly distributed. Monitoring station data revealed that 11 out of 40 stations recorded 'Severe' air quality. The Anand Vihar area was the worst affected, registering a peak AQI of 430. The remaining 29 stations reported readings in the 'Very Poor' range.
Fog Disrupts Life, Weather Hampers Dispersion
Compounding the pollution problem was a persistent dense fog that severely disrupted early morning life. The India Meteorological Department (IMD) sounded an orange alert for dense to very dense fog at several places for Saturday morning. This condition is likely to persist until at least December 22.
On Friday, visibility dropped to critical levels. The Safdarjung observatory, Delhi's primary weather station, recorded zero visibility between 5:30 AM and 7:30 AM, which improved only slightly to 100 metres by 8 AM. Palam recorded visibility as low as 50 metres during the same early morning hours.
Meteorologists attribute the lingering pollution to highly unfavourable weather conditions. The ventilation index, a measure of the atmosphere's ability to disperse pollutants, is expected to remain below 6,000 m²/s in the coming days. Coupled with wind speeds largely under 10 kmph, these conditions create a stagnant environment where pollutants accumulate near the ground.
Sources and Forecast Remain Grim
An analysis of pollution sources for Friday identified the transport sector as the leading contributor to Delhi's PM2.5 emissions at 15.72%, followed by industrial units at 7.8%. Among external sources, emissions from neighbouring regions played a significant role, with Jhajjar contributing 16%, followed by Rohtak (approx. 5%) and Sonipat (approx. 3%). Road dust and construction activities together accounted for about 4% of the PM2.5 load.
The forecast from the Indian Institute of Tropical Meteorology (IITM) offers little respite. It predicts that Delhi's air quality will fluctuate between 'Severe' and 'Very Poor' over the next six days. While Saturday is expected to remain in the 'Very Poor' category, a further deterioration into the 'Severe' zone is likely over the subsequent two days. The IMD reported that Friday's maximum temperature settled at 22°C, close to the seasonal average, while the minimum was 9°C, slightly above normal.
The combination of dense fog, low winds, and cold temperatures is creating a perfect storm for poor air quality, with authorities urging citizens, especially those with respiratory ailments, to take necessary precautions. The situation underscores the ongoing challenge of winter pollution in the Indo-Gangetic plains.
