Gov. Kate Brown's order -- which will take effect Friday -- is generally for everyone ages 5 and up, regardless of vaccination status.
Oregon already was one of a few states with an indoor mask mandate for people regardless of whether they've been vaccinated. The new outdoor order comes as the spread of COVID-19 has increased in the state and around the country, with the rise to prominence of the highly contagious Delta coronavirus variant
"The Delta variant is much more contagious than previous variants we've seen, and it has dramatically increased the amount of virus in our communities," Brown said Tuesday. "Masks have proven to be effective at bringing case counts down, and are a necessary measure right now, even in some outdoor settings, to help fight COVID and protect one another."
The new rule will "not apply to fleeting encounters, such as two individuals walking by one another on a trail or in a park," the governor's office said. But it will apply to public spaces where people can't consistently maintain physical distance, such as large outdoor events, the office said.
Exceptions are allowed for people who are actively eating or drinking outdoors, people involved competitive sports or public performance, and the homeless.
While the rule won't apply to outdoor spaces of private residences, "masks are strongly encouraged in those settings" when people from different households can't maintain distance, the office said.
The US Centers for Disease Control and Prevention updated its mask guidance July 27 to recommend that even fully vaccinated people wear masks indoors when in counties with "substantial" and "high" transmission of COVID-19. As of this week, more than 95% of US counties fall under those categories, according to the CDC.
Cases and hospitalizations soar in Oregon
As has happened in the country at large, coronavirus cases and hospitalizations have soared in Oregon since the early summer as the Delta variant increasingly spread.
Oregon has averaged 2,095 new COVID-19 cases a day over the past week -- its second-highest figure of the pandemic, and more than 18 times what the figure was about seven weeks ago, according to Johns Hopkins University data.
Cases have jumped since July 5, when the state saw its lowest average of 2021 (116 per day), according to Johns Hopkins.
More than 980 COVID-19 patients were in Oregon hospitals according to data released Tuesday -- the state's second-highest total recorded in the last 12 months, according to the US Department of Health and Human Services.
That number was as low as 148 on July 12, according to HHS.
Oregon health officials are starting to see cases cluster around outdoor evens such as music festivals, state Health Officer Dr. Dean Sidelinger said Tuesday in a news release from the governor's office.
"Wearing masks in crowded settings -- even outdoors -- will help slow the spread of COVID-19," Sidelinger said.
The-CNN-Wire ™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.