Patna: Katihar, Bhagalpur and Banka are likely to experience heavy rainfall on Sunday, according to the India Meteorological Department (IMD), which issued a yellow alert for these districts on Saturday. An orange alert was issued for thunderstorms accompanied by lightning and gusty winds reaching speeds of 50-60kmph in 19 districts.The districts under the orange alert include Vaishali, Sheohar, Sitamarhi, Muzaffarpur, Madhubani, Darbhanga, Samastipur, Supaul, Araria, Kishanganj, Purnia, Katihar, Madhepura, Saharsa, Khagaria, Bhagalpur, Munger, Banka and Jamui.An IMD official said, “The southwest monsoon has set in over Kerala on Saturday, eight days ahead of the normal date, marking the earliest onset over Kerala since 2009. The tentative date for the monsoon’s arrival in Bihar is between June 10 and June 15.”Scattered rainfall is expected in the western districts of Bihar on Sunday while isolated showers may occur in the remaining parts of the state.On Saturday, light rainfall was recorded in Dehri, Bikramganj, Valmiki Nagar, Araria, Katihar, Bhojpur, Gaya and Patna. The maximum temperature in all districts remained below 40°C. Dehri was the hottest at 39.2°C while Patna recorded a high of 32.3°C.The state’s lowest temperature was recorded in Sheikhpura at 19.9°C. Patna’s minimum temperature stood at 27.2°C. The IMD has predicted that maximum temperatures across most districts will range between 30°C and 32°C on Sunday.