Daw'r cyhoeddiad yn dilyn cynnydd mewn achosion, gydag arolwg diweddar gan y Swyddfa Ystadegau Gwladol yn nodi cynnydd mewn achosion ar draws y DU.
The announcement comes following a rise in cases, with The Office for National Statistics recent survey reporting an increase in cases across the UK. An estimated 1 in 45 people in Wales currently have COVID-19.