The IMD has issued a heavy to very heavy rainfall warning for 16 states/UTs for the next two days. It is very likely over Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, Arunachal Pradesh, Kerala, Puducherry and Uttarakhand on Monday and Tuesday. West Bengal and Sikkim may witness it on Monday, while Haryana, Chandigarh, Delhi and Punjab may witness it on Tuesday.