New Delhi, Oct 29 : Even though Delhi will have mainly a clear sky on Friday, the India Meteorological Department (IMD) data showed that the city's air quality index has dipped to the 'poor' category. While the maximum temperature will rest at 29 degrees Celsius -- four notches below normal, the minimum temperature will be pegged at 14 degrees Celsius -- two notches below normal. The relative humidity at 8.30 a.m. was pegged at 94 per cent. On Thursday, the maximum and minimum temperatures were recorded at 28.5 and 14 degrees Celsius respectively with the relative humidity at 50 per cent. Delhi's Air Quality Index (AQI) has dipped to 273 (poor category) with the level of PM 2.5 and PM 10 pollutants resting at 68 and 143 under 'moderate' category, respectively, according to the System of Air Quality and Weather Forecasting And Research (SAFAR) that falls under Ministry of Earth Science. As per Central Pollution Control Board (CPCB), AQI in Anand Vihar stands at 337 under 'very poor' category, ITO at 221 (poor), Lodhi Road -- 241 (poor), North Campus -- 253 (poor) and that of Pusa road at 277 (poor). An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe. Delhi-NCR's air quality had improved after Sunday's rainfall to satisfactory. AQI was supposed to remain in the same category for the next three days. The pollutants level in the capital and adjoining areas' air started deteriorating since Wednesday. /IANS