Welsh haf

← Proto-Brythonic *haβ̃ (inherited)

← Proto-Celtic *samos (inherited)

← Proto-Indo-European *sm̥-h₂-ó- (inherited)

← Old Welsh ham (inherited)

→ English summer (cognate)

→ Welsh Gorffennaf (compound)

→ Welsh hafau (affix)

→ Welsh hefin (compound)

→ Welsh hafar (compound)

→ Welsh hafod (compound)

→ Irish Samhain (cognate)

→ Irish samhradh (cognate)

→ Manx sourey (cognate)

→ Cornish hav (cognate)

→ Sanskrit समा (cognate)

→ Old Irish sam (cognate)

→ Old Irish Samain (cognate)

→ Old Irish samrad (cognate)