Delhi-NCR pollution is even worse today: Reasons why AQI is ‘severe plus’, and when relief is likely

DElhi and the subject working capital neighborhood (NCR) ar seeing another daytime under a severe blanket of hazardous air quality on Sunday, December 14, following a dramatic spike in pollution levels throughout Saturday. Forecasts indicate the Air Quality Index (AQI) is expected to remain in the "severe" category, with only slight relief anticipated from Monday onwards.The morning readings on Sunday said several areas across Delhi were in ‘severe’ AQI bracket with readings over 400. According to the Central Pollution Control Board's data, Delhi's overall AQI, as of 7 am on December 14, stood at 461, thus in the ‘severe plus’ category. This was worse than Saturday. It improved by one point to 460 by 8 am.Follow | Delhi NCR pollution live updatesThe persistent "severe" air quality is primarily attributed to weather patterns, specifically a Western Disturbance that has caused “very low wind speed” since Friday, HT has reported.According to Mahesh Palawat, vice president at Skymet, this low wind speed has led to a major spike in pollution levels, and due to the western disturbance, "the AQI might remain in this range on Sunday as well".Also read | Delhi schools to move to hybrid mode for students up to Classes 9, 11 as GRAP 4 kicks inDeterioration prompts immediate curbsThe air quality deterioration on Saturday was swift, marking the fourth "severe" day of the year for the national capital.The 24-hour average AQI at 4 pm on Friday was 349 ("very poor"); this figure worsened by over 80 points in 24 hours to settle at 431 at 4 pm on Saturday, according to Central Pollution Control Board (CPCB) data. Readings throughout Saturday confirmed the alarming trend — the AQI was recorded at 401 at 11 am, worsening to 416 by 2 pm, and hitting 457 ("severe+") by 10 pm.Also read | Noida AQI ‘severe plus’ as air quality plummets in Delhi-NCRIn response to this sharp decline, and unlike previous episodes, mitigative measures were announced with a sense of urgency. The Commission for Air Quality Management (CAQM) invoked Stage 3 curbs under the Graded Response Action Plan, which meant more emergency measures came in on Saturday morning after the AQI neared the 400-mark. This was quickly upgraded to Stage 4 by the evening after the CPCB released its 4 pm bulletin showing the average AQI at 431.This marks the first time this season that Stage 4 curbs, which represent the "severe plus" air quality category, have been implemented this season in Delhi-NCR.Sunday’s forecast for pollution in Delhi, surroundingsThe Air Quality Early Warning System for Delhi (AQEWS) suggests the AQI is expected to remain "severe" on Sunday. Weather experts, however, foresee a slight improvement in air quality from December 15 onwards, as wind speeds are expected to increase. However, that does not mean a major change. The AQEWS bulletin confirmed that the air quality is "likely to be in the very poor category from Monday to Tuesday".Further, there might be a slight increase in temperatures. On Sunday, the minimum and maximum temperatures are expected to be around 9–11°C and 23–25°C, respectively. The Capital is also expected to see partly cloudy skies and moderate fog in most places. Shallow fog on Saturday morning already reduced visibility to around 500 meters to 700 meters between 7:30 am and 8 am.What Stage 4 GRAP restrictions meanThe escalation to GRAP Stage 4 has imposed significant restrictions across the NCR to prevent further deterioration of air quality.The Delhi government issued orders requiring all government and private offices within the city to allow 50% of staff to work from home.All schools have been directed to conduct classes for grades up to 9, along with grade 11, in hybrid mode — physical and virtual — with immediate effect.Transport restrictions under Stage 4 include the restriction of Delhi-registered heavy diesel vehicles that are BS-IV and below.This action was taken quickly, contrasting with the previous "severe" spell in November where Grap 4 was not imposed, even though the AQI remained above 400 for several days.NCR hotspots for pollution: Noida worst in IndiaThe entire NCR is grappling with the severe pollution. On Saturday, 22 of Delhi's 39 active monitoring stations recorded an AQI above 400. In the wider NCR, Noida recorded the worst AQI reading in the country at 455 ("severe+"), closely followed by Greater Noida at 442.The CAQM held an emergency meeting and highlighted areas needing improvement. It directed the Delhi government to better manage traffic congestion at various hotspots, control road dust, and ensure proper disposal of municipal solid waste (MSW).The monitoring body also noted that Haryana’s districts within the NCR showed "poor performance in traffic de-congestion, road dust control, and municipal solid waste (MSW) management, particularly in Gurugram".CAQM directed that intensified night patrolling be carried out to curb waste and biomass burning, and that enforcement be intensified through cameras at fuel stations.The current restrictions are apparently a direct result of pressure from increased public criticism, protests, and judicial scrutiny over the previous two weeks.