A man dressed as Santa Claus takes photos with families from behind a glass enclosure in Vaughan, Ontario, Sunday, Dec. 13, 2020, after Vaughan Mills cancelled their seasonal in-person visits with Santa amid the continuing COVID-19 pandemic. York Region will go into lockdown starting Monday. (Cole Burston/The Canadian Press via AP)

Ontario on Monday announced a province-wide shutdown because of a second wave of COVID-19 in Canada's most populous province.

The lockdown will be put in place for southern Ontario from Dec. 26 until Jan. 23, but will lift for northern Ontario on Jan. 9. Health officials criticized the delay, with one top infectious disease doctor saying it was ridiculous to wait wait until the day after Christmas to shut down.

Ontario has had seven straight days of more than 2,000 cases a day. Modeling shows that could more than double in January. Health officials earlier said a four- to six-week hard lockdown could significantly stop the spread of COVID-19.

Toronto, Canada's largest city, had already closed restaurants for indoor dining but schools remained open. All high schools in Ontario will now be closed for in-person learning until Jan. 25. Elementary schools will be closed until Jan. 11.

After COVID-19 cases surged in the spring, Canada flattened the epidemic curve with a lockdown. But as in other countries, COVID fatigue set in, restrictions were relaxed and a second wave was unleashed.

"We have flattened the curve before and we can do it again," Health Minister Christine Elliott said.

Dr. Barbara Yaffe, Associate Chief Medical Officer of Health, said Ontario is in a very challenging and precarious situation.

"There are outbreaks anywhere people congregate," Yaffe said.

A man dressed as Santa Claus greets children from behind a glass enclosure in Vaughan, Ontario, Sunday, Dec. 13, 2020, after Vaughan Mills cancelled their seasonal in-person visits with Santa amid the continuing COVID-19 pandemic. York Region will go into lockdown starting Monday. (Cole Burston/The Canadian Press via AP)

Ontario Premier Doug Ford said the delay until Dec. 26 will allow businesses outside the current lockdown zones to get ready for it. He said it allows restaurants a chance to sell off some of their inventory.

"I'm not comprising anything," Ford said. "I have to be fair to these businesses who have massive inventory."

Dr. Andrew Morris, a professor of infectious diseases at the University of Toronto and the medical director of the Antimicrobial Stewardship Program at Sinai-University Health Network, said Ford is prioritizing the economy over health by delaying.

"Ridiculous. Costing lives. For what?!" Morris said.

The Ontario Hospital Association said in a statement that it was "surprised and disappointed" the lockdown won't happen for another five days

"People across this province need clear public health communication, and the December 26th implementation date sends a confusing message about what they should and shouldn't do at this crucial moment. We are already hearing from hospital and health system leaders who are shocked that the restrictions will not come into effect until after Christmas," the association's president, Anthony Dale, said in the statement.

Dr. Naveed Mohammad, CEO of the William Osler Health System that operates hospitals in a Toronto suburb, said people need to act as if the lockdown had already started.

"Until the people of this province realize what each trip out their home risks for themselves and their loved ones, we won't get through this," he said, noting that hospitals in Brampton, Ontario, are grappling with capacity. "Please stay home, starting today."