The increase was expected as more businesses reopen in addition to recreation and other activities.
The question officials have is whether the rate will increase enough to outpace hospital ICU capacity.
"We are seeing a spike in the number of cases - and that's expected," said Dr. Anthony Cardillo, an ER doctor and CEO of Mend Urgent Care. "What we can't have is a surge."
The virus has a long incubation period so experts say the increase is not necessarily a reflection of the increased crowds related to George Floyd protests, but could be related to gatherings from the Mother's Day and Memorial Day holidays.
However, officials continue to stress that the virus can be spread by someone who doesn't know they have it.
"There is, unequivocally, asymptomatic spread," said Los Angeles County public health director Dr. Barbara Ferrer. "I don't want anyone to get confused that people who are asymptomatic may not be capable of spreading. They are in fact capable of spreading and we all need to keep that in mind,"
More than 50,000 participate in George Floyd protest on streets of Hollywood
Doctors say those who have been attending protests in large crowds without social distancing should act as if they have been exposed to an asymptomatic infected person.
Anyone attending a large protest in public recently would be wise to get tested and to isolate themselves from vulnerable members of their own household, Cardillo said.
"It's quite a conundrum," Cardillo told ABC7 in a Skype interview. "We're dealing with some major social issues that require protesting and people speaking up. At the same time we have to maintain vigilance on this virus. Otherwise we're going to have some really bad outcomes."
Even as people return to work, shopping and appearing in public, he said, they need to maintain vigilance, including face coverings and social distancing.
On Monday, Los Angeles County reported 869 new COVID-19 cases and 11 deaths in its daily update. The totals now stand at 64,690 cases and 2,656 deaths.
The county's highest number of new cases reported in one day was May 26, when 1,671 new cases were reported
Dr. Christina Ghaly, director of Los Angeles County's Department of Health Services, said the rate of transmission of COVID-19 has ticked up slightly.
"While we don't know precisely yet how reopening and the recovery activities will affect transmission of COVID-19, (the rate) does seem to be greater than (one-to-one) and slightly uptrending,'' Ghaly said recently.
In the next one to two weeks, if that trend holds, there should be enough general hospital capacity, but perhaps not enough ICU beds, she said.
"The number of ICU beds may become inadequate in two to four weeks based on the currently available number of beds,'' she said. "DHS ... is watching this availability of ICU beds very closely.''
She urged everyone to continue to follow guidance about wearing masks or face coverings in public, frequently washing hands and maintaining social distancing.
"There are ways to maintain (good public health) practices even as we reenter society and get people back to work,'' Ghaly said. "Please continue to do everything you can to follow these core public health practices. Your actions, my actions have an impact not just on our own health but the health of all of those around us ... We are all in this together.''
The state has released a county monitoring list so that residents can track progress and note areas of concern as elected officials balance safety and economic concerns.
California's public health officer warned that residents shouldn't get the wrong message from businesses opening their doors.
"Just because some businesses are opening doesn't mean your risk for COVID-19 is gone. We all need to continue to keep physical distancing, wash our hands and wear face coverings in public,'' said Dr. Sonia Angell, state public
health officer and director of the California Department of Public Health.
"As we continue to release guidance on how different sections can reopen with modifications, it is important to remember guidance doesn't mean 'go.' Your local health officer will make the final decision about which sectors will open, guided by data specific to your community.''
City News Service contributed to this report.