From 6pm on Tuesday evening more than 430,000 people in Bridgend, Blaenau Gwent, Merthyr Tydfil and Newport will face new lockdowns.
Public Health Wales (PHW) has announced that eight more regions are now being monitored, which “could” face lockdowns.
Dr Giri Shankar of PHW said Cardiff, said, the Vale of Glamorgan, Carmarthenshire, Swansea, Anglesey, Conwy, Denbighshire and Flintshire are now being monitored.
He said the local lockdowns will be in place for a minimum of three weeks to have an effect. He did not rule out a second national lockdown.
He said, “I certainly hope that we don’t get to that position but if case numbers continue to go up and we see more people going into hospital and needing intensive care and we see cases in our vulnerable groups… we might have to consider complete lockdowns.”