The 576MW project in the Irish Sea is nearly complete, only awaiting the completion of the array cabling work, which had been halted since the end of June.
Project developer RWE said that the halt in work was due to a planned five-year DNV GL inspection of the Polar Prince cable-laying vessel.
However, it has now returned to work, and has laid eight more cables since resumption. This means that 127 are now installed, with 34 remaining.
Gwynt y Mor's 160 Siemens 3.6MW turbines were finished being installed at the beginning of July. When it is completed, it will become the world's second largest operational offshore development behind the 630MW London Array.
Gwynt y Môr is owned by German developer RWE Innogy (60%), energy supplier Stadtwerke München (30%) and technology giant Siemens (10%).