The Sept 19 ceremony in Los Angeles was initially due to take place indoors before a limited celebrity audience.
"The Television Academy and CBS have decided to host all ceremonies ... on the Event Deck at L.A. LIVE, directly behind the Microsoft Theater," the Television Academy said in a statement.
The Event Deck in downtown Los Angeles is an outdoor space that includes a large tented area.
The statement said the changes followed discussions with Los Angeles County health and safety experts.
It added there would be further limits on the numbers of those invited to the show, including those nominated for the highest honours in US television.
"Unfortunately, this means not all nominees will be able to attend this year's awards," the organisers said.
Los Angeles last month reimposed the wearing of masks in all indoor public settings and businesses because of rising numbers of coronavirus infections in the second-largest city in the United States.
Last year's Emmy Awards took place in an empty studio with nominees from around the world joining on video screens from their homes and gardens.
Concerns over the Delta variant of the virus on Tuesday prompted singer Stevie Nicks, 73, to cancel five concerts she had scheduled for 2021.
"While I'm vaccinated, at my age, I am still being extremely cautious and for that reason have decided to skip the five performances I had planned for 2021," the former Fleetwood Mac musician wrote on Twitter.
The New Orleans Jazz Festival, due to take place in early October, was cancelled on Monday because of rising cases of coronavirus in Louisiana.