"I know this may not be the grand reopening we might have liked, but we won't get through this on hope alone", said Chief Public Health Officer Dr. Theresa Tam.
"For the spring and summer months, strict adherence to the public health basics of physical distancing, handwashing and cough etiquette must continue as the bare minimum", she said.
"From our perspective, it is an added layer of protection".
Tam said the new guideline comes as provinces begin to allow businesses and services to reopen, bringing more people out of their homes. Tam said mandatory mask use across Canada doesn't make sense because the risk is far different in the Yukon or Prince Edward Island than it is in Montreal or Toronto.
But to do that, Canada needs to step up its testing for the virus, he said.
Stanwick said people should not be using medical-grade masks, since they are needed by health professionals and are in short supply.
Face masks are risky to the health of some Canadians and problematic for some others. That understanding has changed, as it is now known people without symptoms can transmit the virus to others.
He says federal contact-tracers are helping public health authorities in Ontario and are ready to make thousands more calls a day when any province asks.
Her comments were a turnaround from her advice seven weeks ago that people who are not sick should not be wearing a face mask at all.
Spain is now requiring people to wear masks when in public, but so far most Canadian public health officials have only recommended it be done in circumstances where physical distancing is not possible.
Tam said measures to suppress the disease through the summer are essential to buy more time for research and innovation on medical therapies and vaccine development.
Prime Minister Justin Trudeau says Ottawa and the provinces are still working out how to combine forces on a national strategy for improving COVID-19 testing and tracing the contacts of people infected with the novel coronavirus.
"That's my personal choice".
The prime minister said he wears a mask while walking through the halls of Parliament but that when he sits down to debate, the two-metre distance between him and other MPs is reestablished and he removes the mask.
She has emphasized that wearing a mask - whether medical or non-medical - does not replace staying two metres apart from people outside your household and maintaining proper hand hygiene.
"You may have breathing issue that makes it hard to wear a mask, you may have a cognitive issue that makes it hard to wear a mask, so people need to be understanding, respectful of one another and kind".
Trudeau said the government is now working with "number of different partners" on potential contact tracing and exposure notification applications, and that in the coming weeks Ottawa intends to "recommend strongly to Canadians a particular app that will help us manage the spread of COVID-19".
But many experts say masks should be mandatory because they can reduce the amount of airborne droplets that can carry the virus.