The move will allow many businesses to expand capacity and also allows bars to reopen indoors. Theme parks, including Disneyland, will be able to expand capacity from 25% to 35%.
Los Angeles County is the only other county in the Southern California area already in the yellow tier.
"They look good," Orange County CEO Frank Kim told City News Service of Monday's COVID-19 metrics.
Kim said that if the county became eligible on Tuesday, Orange County could open in the yellow tier by Wednesday.
See the map below to find out where your county stands and keep reading to learn what can and can't open in each color-coded category.
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The county's case rate per 100,000 residents was 1.5 as of Sunday, the day the state calculates its weekly averages. The state issues its weekly averages on Tuesdays.
The county has a .09% positivity rate overall, and in the lower socioeconomic communities hardest hit by the pandemic.
"Our numbers are looking really good," Orange County Supervisor Lisa Bartlett said. "We seem to be improving day by day so it doesn't appear the (virus) variants are a concern right now. ... But we still have not reached that 70% herd immunity in Orange County. We still have about 700,000 people to get up to that herd immunity."
The county on Monday reported just 39 newly diagnosed COVID-19 infections, upping its cumulative caseload to 254,783.
City News Service contributed to this report.