Bengaluru:Heavy to very heavy rainfall will occur in Karnataka on Saturday and Sunday as the southwest monsoon advanced into the interior areas of the state on favourable conditions, the Met office said. "With the monsoon being active this week, rainfall in coastal belt, south interior areas and Malnad region will be heavy to very heavy over the next 48 hours," a Met official said on Saturday afternoon. Fisherfolk have been warned against high tide and strong surface winds across the West Coast. Cloudy sky and light to moderate rains are expected in Karnataka's southern region spanning Bengaluru, Mandya and Mysuru over the next 24 hours while it is likely to be weaker in the state's semi-arid northern districts. Heavy rainfall occurred at most places over coastal and south interior areas on Friday, with Gumbo and Kumar in Uttar Kannada district recording 100mm and 90 mm, followed by Mangalore, Shrill and Henagar 60 mm, Paramour, Mudubidre and Subramanya 50 mm. Situated in the state's old Mysuru region, Bengaluru will have a share of rain and thundershowers towards evening with strong winds and temperatures below normal. The city recorded a maxim of 27.5 degree Celsius and a minimum of 19.3 degree Celsius temperatures on Friday and the forecast for Saturday is 28 degree Celsius and 19 degrees Celsius temperature.