Delhi, known for its poor air quality, is facing a rising threat from ground-level ozone pollution, which has increased from 52 micrograms per cubic meter in 2021 to 66 in 2025. While nitrogen dioxide and carbon monoxide levels have shown a gradual decline, the emergence of ozone complicates the air quality landscape. Ground-level ozone forms when sunlight triggers chemical reactions between nitrogen oxides and volatile organic compounds, peaking during the summer months. This seasonal pattern contrasts with particulate pollution, which worsens in winter due to stagnant air. The trend is not isolated to Delhi; cities across the National Capital Region (NCR), including Meerut and Noida, have also reported rising ozone levels. Ground-level ozone can irritate the respiratory system and pose significant health risks, particularly for those spending extended periods outdoors. Tackling this issue is complex, as it requires managing various emissions rather than targeting a single source. Despite some progress in reducing particulate matter, the increasing ozone levels indicate that Delhi's air quality is evolving and becoming more challenging to manage.