The tug-of-war measures, which begin in Wales on Christmas Eve, will initially last until mid-January.
First Minister Mark Drakeford announced yesterday that Wales is moving to another lockdown after Christmas in response to a steady increase in corona virus cases.
The situation will be reviewed every three weeks, i.e. January 18 before the alert level changes to level four.
All essential retail outlets, including close contact services and fitness and leisure centers, will close at the close of business on Christmas Eve.
All hospitality businesses will be closed on Christmas Day from 6 p.m.
Strict restrictions on family reunions, travel, home stays and vacation stays will come into effect from Monday, December 28, when the five-day Christmas period ends.
Alert level is the last date when the four formalities are officially activated.
The ministers pointed out that Wales prioritises a set of national measures to get different areas out of the lockdown at different times.
“We will review the regulations in three weeks,” Drakeford said yesterday.
“If parts of Wales remain in a reliable and sustainable position, we will see if it makes sense to present some regional differences.
“But we do not know until then. Those changes need to be accurate – sustainable and reliable.”
The Welsh government’s Corona virus control plan, published earlier this week, clarifies what steps the Welsh government is taking when it comes time to review the lockdown.
Looking at the seven-day Wales-wide case rate per 100,000 population is the largest. For the seven days leading up to December 11 – the latest figures from Public System Health Wales did not affect a reporting issue related to data system repairs and upgrades – the figure was 377.8.
For Wales to move to the third tier and allow businesses to reopen, the seven-day case rate must be between 150 and 300 per 100,000 population.
Confirmed case rates above the age of 60 should not indicate rapid growth to move to the third column, and the rate of future events over the next two weeks should not be expected to rise significantly.
Across Wales, test positivity rates of five to 10 per cent are required over a seven-day period. According to the latest Public Health Wales, it is currently 20.5 percent.
The population of Wales, where the corona virus is estimated to be present, should be between 0.75% and 1%.
All of these factors will be taken into account by the Welsh Government and the rate of change of these figures.
Concerns about hospital capacity and stress from cases that increase in the future four to five weeks will also be a factor, as will concerns from local health professionals.