origins
English, German, Danish, and Swedish: nickname or byname for someone of a frosty or gloomy temperament, from Middle English, Middle High German, Danish, Swedish winter (Old English winter, Old High German wintar, Old Norse vetr). The Swedish name can be ornamental.
Jewish (Ashkenazic): from German Winter ‘winter’, either an ornamental name or one of the group of names denoting the seasons, which were distributed at random by government officials. Compare Summer, Fruhling, and Herbst.
Irish: Anglicized form ( part translation) of Gaelic Mac Giolla-Gheimhridh ‘son of the lad of winter’, from geimhreadh ‘winter’. This name is also Anglicized McAlivery. Mistranslation of French Livernois, which is in fact a habitational name, but mistakenly construed as l’hiver ‘winter’.
from Balázs Déri
Some families called Winter may descend from the son of Ter-ade-Wayan that is Terra de Wayana - near Amazonia - mentioned in Talmud.
Jews call him Khanina ben Tradyon.
Balázs Déri's view.