A considerable discrepancy in the temperature of , the water and the air is a serious reason for fog formation. In summer the warm air from the dryland descends over the cold surface of the water, in late autumn and in winter the water evaporates from the surface. It is explained by the fact that cooled air masses from the dryland blanket the lake hollow. The ( fog stays mostly on the shoreline bends, coves, bays and at the open inlets of the rivers. And then one can ( see "a wonderful fairy-tale: a sailer with a flowing snow-white sail is sliding at full speed to meet you; or ( a handsome castle of the Middle Ages hangs poised in the air, smoothly descending as if adapting itself where to land better; or swans, their proud heads high, are flowing close up to you..." (Rasputin)
Mirages are observed near the northeastern part of Olkhon Island, at Solnechny (Sunny) Cape and near Bolshoy (Big) Ushkany Island. There are usually 2-6 mirage days a year; in some years their number can be 16.
Quite a number of legends and beliefs are connected with the Baikal mirages.