Very dense fog from overnight to early this (Friday) morning over Uttar Pradesh, Bihar and Odisha reduced visibility to 25 metres at a number of places even ahead of the advent of the two-week peak fog season of the Northern Hemisphere winter from around mid-December.

India Meteorological Department (IMD) said less intense (dense) fog was reported from areas over the rest of the plains in upstream Punjab and downstream West Bengal, Assam, Meghalaya and Tripura relative to the movement of the causative western disturbance.

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