The latest figures show case rates have risen sharply to more than 910 cases per 100,000 people – the highest levels since the start of the pandemic.
Mae'r ffigurau diweddaraf yn dangos bod cyfraddau achosion wedi codi'n sydyn i fwy na 910 o achosion fesul 100,000 o bobl - y lefelau uchaf ers dechrau'r pandemig.