New Delhi, Sep 12 : After a brief interlude, the national capital is again going to witness cloudy sky on the weekend and light rainfall on the first two days of next week, the Indian Meteorological Department stated on Saturday. The weather bureau has issued a green alert for the next two days and yellow for the latter two. IMD has four colour-coded warnings as per the intensity of any weather system -- green, yellow, orange and red. Green alert means no warning, while yellow means be aware. The rainy weather will bring down the mercury and bring respite from the extremely hot and humid weather. The maximum temperature which currently stands at 38 degree Celsius, will plummet to 35 over the next week. According to Kuldeep Srivastava, head of the IMD's regional forecasting centre, the southwest monsoon, which had arrived in Delhi on June 25, is likely to stay longer and withdraw in October. "More than 80 per cent period of four-month-long rainy season has passed, and the country has received around 800 mm of rain so far which is 9 per cent surplus of the LPA," private forecasting agency, Skymet Weather, stated. Meanwhile, the air quality index is in the moderate category, with the particulate matter with a diameter of 2.5 and 10 microns, which are too small to be filtered out of the body, increasing to 53 and 136 micrograms per cubic. "The most fundamental parameter that is making Delhi air quality one of the best in recent years is the speed and direction of the wind in the past few days loaded with recent widespread rain and the lockdown-related widespread cleansing. An ideal example of integrated natural experiment managing Delhi air in check from internal and external sources," stated the System of Air Quality Weather Forecasting and Research. /IANS