New Delhi, Dec. 9 -- Delhi recorded a slight rise in temperature even as its air quality remained in the "very poor" category on Monday. The 24-hour average air quality index stood at 314 at 4pm, marginally higher than Sunday's reading of 308. Through the day, winds strengthened to around 15 km/hr and patches of blue sky appeared, but forecasts by the Early Warning System for Delhi show that pollution levels are likely to stay "very poor" at least until December 12. To be sure, by 10pm, the AQI had dipped slightly to 297, placing the city in the "poor" category, though the official reading remains the 24-hour average at 4pm. Temperatures continued their gradual upward trend. Delhi's minimum temperature settled at 8.7degC, a degree below nor...