The India Meteorological Department (IMD) has issued dense to very dense fog warning for 21 states/UTs for January 2 (Friday). It is very likely over Arunachal Pradesh, Assam, Meghalaya, Bihar, Himachal Pradesh, Jammu and Kashmir, Ladakh, Nagaland, Manipur, Mizoram, Tripura, Uttar Pradesh, Uttarakhand, West Bengal, Sikkim, Haryana, Chandigarh, Delhi, Odisha, Punjab and Rajasthan.