<span style="color: #222222;">Delhi recorded its lowest pollution level of the year today following a spell of rain. The Central Pollution Control Board (CPCB) said, the air quality improved significantly, but it still remained in the very poor category.</span><br />'' <br />'' <span style="color: #222222;">The CPCB said, the overall Air Quality Index (AQI) in the city was 347. An AQI between 100 and 200 comes under 'moderate' category, 201 and 300 is considered 'poor', 301 and 400 is 'very poor' and that between 401 and 500 is 'severe'.</span><br />'' <br />'' <span style="color: #222222;">Delhi's air quality has been oscillating between the upper range of the 'very poor' and 'severe' category for the past two weeks.</span>