New Delhi, Oct 28 : The India Meteorological Department (IMD) has forecast a clear sky for Delhi-NCR on Friday with the maximum temperature being recorded at 29 degrees Celsius and the minimum at 15 degrees Celsius. Meanwhile the relative humidity at 8.30 a.m. was recorded at 78 per cent. According to the IMD, the next four days could have a clear sky and the remaining two could have a partly cloudy sky. After having a satisfactory and moderate air quality, Delhi's AQI has dipped to 'poor' category. The level of PM 2.5 and PM 10 pollutants in the capital stand at 108 (poor) and 229 (moderate), whereas the overall AQI of the city is at 259, according to the System of Air Quality and Weather Forecasting And Research (SAFAR). As per Air Quality Early Warning System for Delhi that comes under Ministry of Earth Sciences, the air quality over Delhi-NCT is likely to remain in Poor category on October 28. "The air quality over Delhi-NCT is likely to deteriorate gradually and remain in Poor category on October 28 and Very Poor category on October 30. The Outlook for subsequent 5 Days: The air quality is likely to remain in Very Poor category and PM2.5 to be the predominant pollutant," it said. The crop residue burning fire points were observed in Punjab (279), Haryana (93) and Uttar Pradesh (58) on Wednesday. The contribution of biomass burning in PM2.5 concentration is likely to be approximately 20 per cent on Thursday. /IANS