The county reported 5,087 new COVID-19 cases and 37 deaths on Thursday.
The staggering numbers came after a much-debated ban on in-person dining, with county health officials painting a dire picture of the current surge, saying the transmission rate has reached its highest point since March and could overwhelm hospitals within a month.
Officials urged residents to avoid Thanksgiving gatherings and not to celebrate with people who live outside their household in an attempt to stop the spread of the coronavirus.
RELATED: How much are restaurants contributing to the spread of COVID-19 in LA County?
How much are restaurants contributing to the spread of COVID-19 in LA County?
Thanksgiving amid a pandemic and evolving county health guidelines looks different for everyone.
In most of L.A. County, outdoor dining is prohibited for at least three weeks. People lined up with face coverings to wait for take-out orders at restaurants instead on Thursday.
In Pasadena, where outdoor dining is still allowed, restaurants were busy in the morning and afternoon.
RELATED: Pasadena to keep outdoor dining despite LA County restrictions
Pasadena to keep outdoor dining despite LA County restrictions
Lancaster Mayor Rex Parris says, like Pasadena, he wants to establish the city's own health department, in part to allow restaurants to remain open.
"We're having a meeting next week with the restaurant owners. I'm not talking about the chains, I'm talking about the family-owned businesses," Parris said.
L.A. County public health leaders have stressed outdoor dining poses a unique risk because people are not wearing a face covering and potentially eating with people from other households.
They warn hospitals are nearing bed capacity and they estimate 1 in every 145 L.A. County residents is currently infectious with COVID-19 and may not know it. The estimate does not include people who are already self-isolating or who are currently in hospitals.
City News Service contributed to this report.