Delhites woke up witnessing a cloudy morning and the air quality plunged into the poor category. The overall air quality index (AQI) was 280, according to the System of Air Quality and Weather Forecasting And Research (SAFAR) on Friday. Some areas in the national capital including Pusa Road, Lodhi Road, IIT Delhi and Ayanagar recorded air quality in the poor category with an AQI of 249, 235, 249 and 239 respectively. According to SAFAR, AQI between the range of 51 and 100 is considered as satisfactory or very good , 101-200 is moderate , 201-300 falls under the category of poor . While 300-400 is considered as very poor , levels between 401-500 fall under the hazardous category.