Delhi-NCR's air quality remains alarmingly poor this winter, even though farm fires are at a multi-year low. Pollution levels in October and November mostly stayed between 'very poor' and 'severe'. A mix of PM2.5, nitrogen dioxide (NO₂), and carbon monoxide (CO) from vehicles and local sources is to blame. The Centre for Science and Environment (CSE) found that 22 Delhi monitoring stations recorded CO levels above safe limits for over half the days assessed. Dwarka Sector 8 topped the list with 55 days, followed by Jahangirpuri and Delhi University's North Campus with 50 days each. Pollution hotspots have grown since 2018, when only 13 places were flagged. Jahangirpuri is now the most polluted area, with an annual PM2.5 average of 119 micrograms per cubic meter, followed by Bawana, Wazirpur, Anand Vihar, Mundka, Rohini, and Ashok Vihar. Smaller towns like Bahadurgarh saw long smog stretches, lasting up to 10 days, showing that the entire NCR acts as one large polluted zone. CSE’s analysis shows that early winter pollution stabilized at harmful levels mainly due to local emissions, while stubble burning’s share dropped. From the data, PM2.5 and NO₂ levels spiked together during traffic hours, pointing to vehicle emissions as a key cause. CO also crossed limits at many sites. Anumita Roychowdhury, CSE executive director, said, "This synchronised pattern reinforces that particulate pollution spikes are being fuelled daily by traffic-related emissions of NO₂ and CO, especially under low-dispersion conditions." She added, "Yet, winter control efforts remain dominated by dust measures, with weak action on vehicles, industry, waste burning and solid fuels." Stubble fires contributed less than 5% to Delhi’s pollution for most of the early winter, rising slightly on some days. This kept extreme pollution bursts low but did little to improve daily air quality. PM2.5 was the main pollutant on 34 days, PM10 on 25 days, ozone on 13 days, and CO on two days in November. The Air Quality Index hovered in 'very poor' to 'severe' categories, highlighting the strong impact of traffic, industry, waste burning, and domestic fuel use. Compared to last year, PM2.5 levels dropped by about 9%, but average pollution this winter showed almost no real change against the past three years. The annual PM2.5 average rose sharply to 104.7 µg/m³ in 2024, reversing earlier improvements. The report suggests urgent actions like electrifying transport, scrapping old vehicles, expanding public transit and cycling paths, and cutting waste burning to tackle pollution effectively. On December 1, 2025, Delhi’s 3 p.m. AQI was 303, marked as 'very poor', according to the CPCB.