Alberta's premier says more than 80,000 residents who fled Canada's main oil sands town because of a massive wildfire could return home starting on June 1 if conditions are deemed to be safe.

Premier Rachel Notley said Wednesday the re-entry will be done in stages and will be voluntary. Those who live in the least damaged areas will be allowed in first.

Notley says schools will not reopen again until the fall and there will be a boil water advisory in effect for all of June.

About 80,000 Fort McMurray residents were forced to evacuate more than two weeks ago. About 2,400 structures were destroyed in Fort McMurray, but 90 percent of the city remains intact, including essential infrastructure like the hospital, water treatment plant and the airport.