New Delhi, Dec 25 : After crossing the 400 or 'severe' mark a day ago, Delhi's Air Quality Index (AQI) improved marginally on Saturday to 398, which is the lower end of the 'very poor' category. "The air quality is likely to improve further but remain in the 'very poor' category on December 25 and 26. The outlook for subsequent five Days: The air quality is likely to improve significantly from December 27 when AQI to reach in 'poor/moderate' category," said the air quality and weather bulletin. 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 between 401 and 500 is considered 'severe'. The level of PM10 and PM2.5 pollutants were recorded in the 'very poor' category, respectively. Meanwhile, the Delhi's maximum and minimum temperatures at 9 a.m. on Saturday were recorded at 23 and 7 degrees Celsius, respectively, according to the India Meteorological Department (IMD). The relative humidity at 8.30 a.m. wass 95 per cent. The IMD has also predicted light rain or drizzle in Delhi from December 26 to 28. As per the forecast, there will be generally cloudy sky with light rain on December 26, cloudy sky with light rain or drizzle on December 27 and mostly cloudy sky with the possibility of rain or thunderstorm on December 28. /IANS