Kolkata experienced 'poor' air quality on New Year's Day, with PM2.5 levels exceeding safe limits across several monitoring stations. Jadavpur recorded an AQI of 315, in the 'very poor' category. An environmental group, Sabuj Manch, alleged that firecracker use violated court-mandated time limits, continuing until 2 am. However, a West Bengal Pollution Control Board official stated that fireworks activity was lower than the previous year and celebrations largely ended by 12:30 am, adding that winter conditions also contribute to air quality issues.