Nearly 40 counties are on the state's watch list because of concerning COVID-19 trends.
UPDATE, Aug. 23, 12:15 p.m.: Orange County was removed from the watch list Sunday. See more below.
As most of California has moved into Phase 3 of reopening, the state is once again seeing COVID-19 cases and hospitalizations rise dramatically.
App users: For a better experience, click here to view the full map in a new window
The Department of Public Health has a watch list of counties that are being monitored for worsening coronavirus trends. In each case, the state is working with local health departments to identify the source of the problem and provide assistance as needed.
LATEST FROM GOV. NEWSOM: Newsom says power outages 'very likely' through Wednesday, announces changes to COVID-19 watch list
There are six criteria that will land a county on the watch list:
If a county is on the watch list for three days or longer, the state will order them to roll back reopening, Gov. Gavin Newsom said.
Alameda County: Even though Alameda County has reopened slower than every other county in the Bay Area, the county says it's still feeling the effects of reopening because county residents work and socialize across county lines. They've seen a steady rise in cases over the past several weeks as a result. Public health officials think socializing without masks is also contributing to a rise in COVID-19 cases, as is increased transmission among health care workers.
Butte County: Elevated disease transmission is likely due to increased private gatherings and outbreaks at congregate living facilities. "While they have experienced an increase in cases and hospitalizations have increased slightly, the number of COVID patients in ICU have remained low and the hospitals are not concerned about surge at this time," the state says.
Colusa County: Increased transmission in Colusa County has been traced back to increased family and social gatherings, the state says. To combat the spread of the virus, the county must increase contact tracing and post daily on social media about the importance of face coverings and social distancing.
Contra Costa County: Contra Costa was added to the watch list, taken off for a few days, and now is back on. An increase in hospitalization is what's concerning here. The state advises Contra Costa holds off on reopening more businesses, such as indoor dining, gyms and movie theaters.
Fresno County: Fresno is in trouble for "elevated disease transmission," especially in skilled nursing facilities and Avenal State Prison. (While the prison is in Kings County, some of its employees live in Fresno and have brought the virus back into the community). Controlling outbreaks at those congregate facilities is key to getting Fresno off the list, DPH says.
Imperial County: DPH is attributing the problem in Imperial County to two factors: "U.S. citizens coming across the Mexican border seeking healthcare" and inadequate hospital staffing. The county is being asked to ramp up testing, contact tracing, transport patients to hospitals in other counties and create more alternative care sites.
Inyo County: Inyo County has seen an increase in COVID-19 transmission, resulting in a rapid rise in positive case and test positivity rates. The number of hospitalized COVID-19 positive patients has also increased, the state says.
Kern County: Kern County was removed from the watch list on July 13, then added back the following week. The recent spike in cases is partially due to an "exponential expansion" in testing, the state says, as well as outbreaks in nursing homes and prisons. Multi-household social gatherings are also contributing to increased transmission. The county is working to control outbreaks at nursing homes and prisons, plus continue outreach to the community about the importance of disease prevention.
Kings County: Not only is there elevated disease transmission and rising hospitalization in Kings County, but hospitals are also getting worryingly close to capacity. An outbreak at Avenal State Prison has spread the virus throughout the community, plus Kings County hospitals have admitted patients from other areas. Action items include getting the prison outbreak under control, as well as making sure hospitals are properly equipped to treat patients and protect staff.
Los Angeles County: One reason Los Angeles County has nearly half of the state's COVID-19 cases is because of its huge population and the fact that it's doing so much testing. Still, the county is being asked to keep a close eye on positivity rates as an indicator that community transmission is on the rise. They're also testing every resident and staff member at all 235 skilled nursing facilities in the county.
RELATED: Here's why LA County is seeing an increase in COVID cases, but decline in deaths
Madera County: There are two main concerns in Madera County: increased transmission and limited hospital capacity. Social gatherings, large household transmission and workplace transmission are likely to blame, officials say. In addition to public messaging on curbing COVID-19 spread, the county is also being told to prepare for increased hospital capacity by setting up alternative care sites and working with nearby counties to transfer patients.
Marin County: The spike in cases in Marin is largely due to a massive outbreak at San Quentin State Prison and elevated transmission among the county's Latinx community. The county needs to work with the corrections department to get the San Quentin outbreak under control and to make sure those in vulnerable communities have access to testing and care.
Mendocino County: Mendocino County is experiencing elevated COVID-19 transmission and an increase in hospitalizations. Drivers of this include family and community gatherings, increased community spread, increased spread among the Latino population within large household settings, outbreaks in congregate livings such as skilled nursing and assisted living facilities, the state says.
Merced County: Merced has seen outbreaks traced back to work settings and large household, particularly in the Latinx community, the county says. To mitigate the situation, the county will increase multilingual messaging on the importance of testing and face coverings. They're also going to work to make businesses safer so they don't have to shut down.
Monterey County: Community and workplace transmission are both on the rise in Monterey County, according to the public health department. The county's action items include more testing, more contact tracing and expanding outreach to communities disproportionately affected by COVID-19.
Riverside County: The state has identified five factors contributing to a rise in cases in Riverside County: outbreaks at prisons and nursing homes; large public protests where people weren't wearing face coverings; patients coming from Imperial County for treatment; patients coming from Northern Baja California for treatment; and an increase in social gatherings. In addition to increasing testing, the county is being told to educate residents on the importance of wearing face coverings.
WATCH: Here's what Riverside County's antibody study says about herd immunity
Sacramento County: "Community transmission due to holiday gatherings amongst large families" has landed Sacramento County on the state's watch list. The county is being asked to increase public messaging about social distancing and face coverings and increase testing in hot spot communities.
San Benito County: New clusters here have been traced back to household contacts, social gatherings and businesses. The county will work with businesses to make sure symptomatic employees stay home and get tested.
San Bernardino County: Increase transmissions here are largely attributable to large gatherings, workplaces, nursing homes, jails and prisons, and patients being transferred from Imperial County. The county needs to ramp up testing, contact tracing and "working with labs and employers to increase turn-around time from diagnosis to isolation." Residents also need to do a better job of wearing face coverings to mitigate spread.
San Francisco County: San Francisco has been added to the state's watch list, said Mayor London Breed in a press conference Friday. As a result, indoor malls and non-essential offices will close Monday.
San Joaquin County: The problem in San Joaquin County is a rise in hospitalizations and increasingly limited hospital capacity. The suspected drivers of this are increased social gatherings combined with workplace transmissions, the state says. In response, the county is being told to "increase public messaging on the importance of personal protection measures and the risks involved with mass gatherings in multiple languages."
San Luis Obispo County: The county is seeing an uptick in transmission since reopening businesses that encourage mingling and an "increase in certain community sector perception that the pandemic is not serious." The county is being asked to enforce distancing between patrons and employees at businesses and do rapid turnaround testing for known COVID-19 contacts, among other action items.
San Mateo County: San Mateo County is experiencing an elevated case rate that exceeds the state threshold. The county sees roots of community transmission related to social gatherings without sufficient physical distancing and wearing of facial coverings, as well as higher exposure for residents performing work that involves person-to-person contact and crowded housing conditions that make home isolation difficult, the state says.
WATCH: Here's a breakdown of Newsom's four stage plan to reopening California
Santa Barbara County: Santa Barbara County is experiencing increasing hospitalization related to increasing cases in our north county region. Drivers of this increase include 1) community transmission due to gatherings, 2) workplace transmission and household transmission; 3) SNF outbreaks; and 4) increase in widespread community testing, the state says.
Santa Clara County: Santa Clara County is experiencing increased hospitalization. Drivers of increased hospitalization of COVID-19 patients may include: 1) increased transmission in the community; 2) patient transfers from outside the county; 3) patient transfers from long term care facilities; 4) /or increased transmission among residents or individuals from neighboring counties who seek care in hospitals in Santa Clara County, the state says.
Solano County: A large outbreak among farmers who work at Sonoma and Napa vineyards (but live in Solano County) is partially to blame for a rise in COVID-19 cases here. The county says those cases are in the "many dozens." Other cases can also be traced back to family and social gatherings on weekends. The county is being told to educate workers on social distancing using Spanish translators and work with businesses to ensure working conditions are safe.
Sonoma County: The county is now on the state's watch list after a surge of new cases. Restaurants, wineries and tasting rooms can not operate indoors. The county health order also includes movie theaters, family entertainment centers, zoos, museums and card rooms. Bars, clubs, breweries and brewpubs must close whether they operate indoors or outdoors. The order will remain in effect through at least August 2.
Stanislaus County: Stanislaus County is experiencing an "increase in outbreaks and clusters related to family gatherings, businesses (in and out of county) and healthcare facilities." Health officials believe people may not be following face covering and social distancing guidelines. The county is also being asked to increase rapid contact tracing in order to isolate positive cases more quickly before they spread widely.
Tehama County: Tehama County is experiencing elevated case counts. Drivers for this include clusters in the following areas: 1) household contacts, 2) social gatherings, 3) workplace and 4) group camping trips.
Tulare County: Tulare County is interesting because not only are they reporting more coronavirus transmission, but also "Increased hospitalizations and ICU utilization have been related to multiple conditions other than COVID-19." Preventing outbreaks at nursing homes and increasing public awareness are two action items for the county.
Ventura County: Increased cases in Ventura County have resulted in increased hospitalizations. Officials believe the increase comes from transmissions at large gatherings, in overcrowded housing, at essential workplaces and at nursing homes. They also believe they are detecting more cases since opening more drive-thru testing facilities. Action items for the county include: enhance contact tracing, make sure nursing facilities have protective equipment and continue messaging on social distancing and hygiene.
RELATED: Severe shortage of ICU beds reported in Ventura County
Yolo County: Increased social gatherings and workplace transmission are to blame for a rise in cases, but so is the expansion of testing at nursing homes, the state says. The county is being asked to better enforce health and safety measures, as well as boost outreach to residents regarding face covering mandates.
Yuba County and Sutter County: Yuba and Sutter counties are experiencing elevated disease transmission. Drivers of this include household clusters relating to friend and family gatherings and workplace transmissions. Forty percent of new cases are of unknown origin due to people not able or not willing to provide information on the source of exposure.
This story will be updated as counties are added and removed from the list. You can find more information from the California Department of Public Health.
For the latest updates and resources on the coronavirus, visit abc7.com/coronavirus.