köken: Likely from Old Occitan eissalot and its variants (e.g. eyssiroc), from Massalian Ancient Greek *ἐξαλώτης (*exalṓtēs), from ἔξαλος (éxalos, "out of the sea" → "wind from the southeast"). Traditionally thought to be a derivative of Arabic شرق (šarq, “east”). Akin to Italian barocco. Compare Sicilian sciroccu.
köken: From Proto-Finnic *kakko ~ *kaakko (“southeast”). Cognate to Estonian kagu and Ingrian kakko. Possibly related to kaakkuri, in which case the cardinal direction meaning could derive from a meaning like "the direction where migratory birds come from".
From Arabic شَلُوق (šalūq), شَلُوك (šalūk, “southeastern wind”), probably acquired through Italo-Romance, see Italian scirocco. A doublet may be at hand in xellug (“left”), which see.