The air quality in Delhi improved to 'poor' category from 'very poor' on Sunday morning, according to Central Pollution Control Board (CPCB). The national capital recorded AQI of 269 at 7 am today, marking an improvement from 305 recorded at 4 pm on Saturday. Shadipur recorded the worst AQI level of 335 while Mandir Marg recorded lowest AQI at 158.