The COVID-19 pandemic in California began earlier than in some other parts of the United States. Ten of the first 20 confirmed COVID-19 infections in the United States were detected in California, and the first infection was confirmed on January 26, 2020. All of the early confirmed cases were persons who had recently travelled to China, as testing was restricted to this group, but there were some other people infected by that point. A state of emergency was declared in the state on March 4, 2020. A mandatory statewide stay-at-home order was issued on March 19, 2020; it was ended on January 25, 2021. On April 6, 2021, the state announced plans to fully reopen the economy by June 15, 2021.

As of June 16, 2022, the California Department of Public Health (CDPH) has reported 9,199,942 confirmed cumulative cases and 91,240 deaths in the state. This was the highest number of confirmed cases in the United States, but because the state has the highest population of any US state, it also had one of the lowest rankings (41st highest out of 50 states) for confirmed cases per capita. It has the highest count of deaths related to the virus, but a relatively low (35th highest) count of deaths per capita. , California had administered 40,669,793 COVID-19 vaccine doses, the largest number of doses nationwide, and was one of the highest ranked (11th out of 50 states) in terms of per-capita dose administration.

A bipartisan effort of politicians and owners of restaurants, bars, gyms, spas, and other small businesses harmed by lockdown restrictions attempted to recall Governor Gavin Newsom in 2021; he won the election with 66% support.

California is the origin of the Epsilon variant of SARS-CoV-2, which, in March 2021, accounted for 35% of all confirmed cases of COVID-19 in the state at that time.

Timeline

First detection Although later events suggested that COVID-19 had been present within California in December 2019, the virus was not detected for the first time until late January 2020: On January 26, 2020, the Centers for Disease Control and Prevention (CDC) confirmed the first case in California. The person, who had returned from travel to Wuhan, China, was released from the hospital in Orange County on February 1 in good condition to in-home isolation. On January 31, the CDC confirmed the state's second case, a man in Santa Clara County, who had recently traveled to Wuhan. The man recovered at home and was released from in-home isolation on February 20.

On January 29, 2020, as disease containment protocols were still being developed, the U.S. Department of State evacuated 195 of its employees, their families, and other U.S. citizens from Hubei Province aboard a chartered flight to March Air Reserve Base in Riverside County. There were concerns at the time that allowing Americans to return from overseas might spread COVID-19 within California and the rest of the US.

On February 2, the CDC confirmed the state's third case in a woman in Santa Clara County, California, who had recently traveled to Wuhan. On the same day, the CDC reported the country's tenth and eleventh cases in San Benito County, including the second known instance of human-to-human transmission.

On February 5, the U.S. evacuated 345 citizens from Hubei Province and took them to two air bases in California, Travis Air Force Base in Solano County and Marine Corps Air Station Miramar, San Diego, to be quarantined for 14 days.

First death On February 6, 2020, a woman from San Jose, California became the first COVID-19 death in the United States, though this was not discovered until April 2020. The case indicated community transmission had been happening undetected in the state and the United States, most likely since December 2019. On March 4, it was separately reported that the first coronavirus fatality in the state had instead occurred in Placer County.

On February 15, the government evacuated 338 U.S. nationals stranded aboard the cruise ship Diamond Princess, which had been held in quarantine in Yokohama, Japan. Fourteen of those repatriated people were infected with the virus. Five more nationals with COVID-19 were evacuated from the ship the following week and were quarantined at Travis Air Force Base; several more cases among the evacuees were later confirmed.

On February 26, 2020, a confirmed case of unknown origin was announced about a resident of Solano County. The UC Davis Medical Center in Sacramento had asked the CDC to test for SARS-CoV-2, even though the person did not meet the CDC's criteria for testing at the time, which required a likely exposure to an infected person through either travel or close contact with someone known to have COVID-19. The CDC eventually agreed to do the test, which proved the person had COVID-19. After this first confirmed case of community transmission in the United States, the CDC revised its criteria for testing patients for SARS-CoV-2 and issued new guidelines for healthcare workers.

State of emergency On March 2, 2020, amidst concerns over the spread of coronavirus in the state, Governor Gavin Newsom declared a state of emergency in California. Newsom issued a mandatory statewide stay-at-home order on March 19, 2020; it would be ended 10 months later, on January 25, 2021. This order caused the closure of schools, restaurants, meeting places, and many workplaces.

On March 24, a teenager who tested positive and died in Lancaster, part of Los Angeles County, appeared to have become the first individual in the United States under the age of 18 to die of COVID-19. However, while he had COVID-19 at the time of his death, it is unclear whether COVID-19 caused his death.

On June 18, 2020, Newsom ordered a statewide mask mandate due to the rising number of cases and deaths, requiring citizens to wear masks or other coverings in most public spaces with a few exceptions. Many local governments had previously dropped mandatory mask-wearing measures. On July 9, he reported a new record number of COVID-19-related deaths in the state. By July 22, California surpassed 409,000 COVID-19 cases, surpassing New York for the most in the nation.

On August 19, 2020, Dr. Sonia Y. Angell resigned as the CDPH Director and State Public Health Officer. Governor Gavin Newsom indicated Angell's resignation was related to data issues with the California Reportable Disease Information Exchange (CalREDIE) system that resulted in nearly 300,000 backlogged COVID-19 test results. On August 10, 2020, Sandra Shewry was appointed as acting director and Dr. Erica Pan, California state epidemiologist, was named acting state public health officer.

By September 3, 2020, Hispanic and Latino Americans comprised up to 60% of COVID-19 cases in the state, ostensibly due to the large population of the demographic and many of them being a part of the essential workforce. Filipino Americans were the second-most affected, in part due to a high percentage of workers in healthcare on the frontlines, and as well as having a very high percentage of essential workers much like Latino Americans in California.

On October 26, 2020, San Francisco and Oakland phased out Google's sister company Verily's COVID-19 testing system following concerns about patients’ data privacy and complaints about its funding, which despite intention to boost testing in low-income Black and Latino neighborhoods was benefiting higher-income residents in other communities.

On December 30, 2020, a confirmed case of a new, more contagious SARS-CoV-2 variant from the United Kingdom was reported in Southern California. On January 6, 2021, the CDC announced that it had found at least 26 confirmed cases of the more contagious SARS-CoV-2 variant in California. As of March 2, 2021, 189 sequences in the B.1.1.7 lineage have been detected in California since the lineage was first identified.B.1.1.7 Lineage Report. Alaa Abdel Latif, Karthik Gangavarapu, Emily Haag, Nate Matteson, Julia L. Mullen, Ginger Tsueng, Mark Zeller, Chunlei Wu, Andrew I. Su, Laura D. Hughes, Kristian G. Andersen, and the Center for Viral Systems Biology. outbreak.info, (available at https://outbreak.info/situation-reports?pango=B.1.1.7 ). Accessed 2 March 2021.

As of March 2, 2021, 1,608 sequences in the B.1.427 lineage and 3,903 sequences in the B.1.429 lineage had been detected in California.

The statewide mask mandate ended on June 15, 2021, with the state recommending outdoor events with 10,000 or more attendees and indoor events of 5,000 or more attendees recommended by the state to require masks for individuals without proof of vaccination or a negative test. The mandate was reinstated for one month on December 15, 2021 in response to a surge in cases due to the Omicron variant. On January 5, 2022, the mandate was extended for another month, ending on February 15. The state's mask mandate for K-12 schools was lifted on March 12, 2022.

On February 28, 2023, the state of emergency officially ended.

Equipment shortage California formerly had a strategic stockpile of medical supplies for responding to epidemics. In 2006, then-Governor Arnold Schwarzenegger ordered creation of an epidemic-ready medical equipment stockpile, including three 200-bed mobile hospitals with 50 million N95 respirators, 2,400 ventilators, and 21,000 additional patient beds. Governor Jerry Brown cut the budget for warehousing and keeping up the reserve in 2011, responding to the Great Recession economic downturn.

Personal protective equipment for healthcare workers As early as January 2020, a survey by the California Department of Public Health found that many Californian health care providers were having trouble obtaining adequate personal protective equipment (PPE), such as masks, gowns, and eye protection. By mid-March, 2020, when Newsom issued the first statewide shelter-in-place order, 220 of 292 California hospitals surveyed already reported that they were having to limit use of masks, often severely. Even with limitations in place, Newsom estimated that California healthcare facilities were still using about 46 million masks each month during the pandemic.

As safety equipment shortages continued throughout the first months of the pandemic, many doctors, nurses and emergency medical service workers expressed fears and frustrations at being asked to reuse safety gear or wear homemade and less effective masks and at the overall lack of proper PPE, which does not provide adequate protection from COVID-19 exposure. , local agencies reported 127 deaths from a total of 23,513 confirmed positive cases among healthcare workers in California.

Newsom's administration made several attempts to procure masks and other protective equipment for healthcare workers, including:

multiple attempts at large-scale mask purchases, including failed deals with Blue Flame Medical, which was investigated by the US Department of Justice, and Bear Mountain Development Co., as well as a successful, if initially delayed, purchase from BYD; and a marketplace portal where individuals and businesses could offer PPE for donation or sale, attracting many small donations as well as fraudulent business posts that overwhelmed the site managers.

, California's stockpile reached approximately 86 million N-95 masks and 111 million surgical and procedural masks.

Hospitals and ventilators