An Etymological Dictionary of the German Language/Annotated/Sommer

Sommer, masculine, ‘summer,’ from the equivalent Middle High German sumer, Old High German sumar, masculine; common to Teutonic in a similar form; compare Dutch zomer, Anglo-Saxon sumor, English summer, Old Icelandic sumar. Sanscrit samâ, ‘year,’ Zend ham, ‘summer,’ Armenian amaṙn, ‘summer’ (but am, ‘year’), Old Irish sam, samrad, Cymric ham, haf, ‘summer,’ are cognate terms with different suffixes. Compare Lenz, Winter, and Herbst.