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Coronavirus Map: Tracking COVID-19 cases across the Bay Area and California - San Francisco Chronicle

New reported cases and deaths in the Bay Area, by day

Jan. 5 March 7 May 7 July 7 0 2,000 4,000 6,000 8,000 7-day average

Jan. 5 March 7 May 7 July 7 0 50 100 150 200 7-day average

New reported cases and deaths in California, by day

Jan. 5 March 7 May 7 July 7 0 10,000 20,000 30,000 40,000 50,000 7-day average

Jan. 5 March 7 May 7 July 7 0 200 400 600 800 1,000 1,200 7-day average

Sources: U.S. Centers for Disease Control and Prevention, California Department of Public Health and county public health departments, Chronicle reporting

The seven-day trailing average represents the average number of cases or deaths reported each day over the weeklong span ending on the given day. It is used to account for daily variances in reporting and large one-off changes in daily counts, such as April 20 when nearly 1,500 cases were reported in L.A. County as the result of a lab clearing a large backlog. Some counties do not provide daily updates which, combined with daily variances in the number of tests given, could result in randomly higher or lower counts for daily reported cases.

How many people are hospitalized?

The number of people hospitalized with COVID-19 in California and in the Bay Area still is far below the totals reached during the winter surge when more than 20,000 Californians were admitted with virus-related symptoms. Hospitalizations and ICU availability were key numbers used to determine the level of restrictions while California was shut down and continue to be monitored as the region experiences a fourth surge driven by the delta variant.

Confirmed ICU and non-ICU COVID-19 patients in Bay Area hospitals

April 1 June 27 Sept. 22 Dec. 18 March 15 June 10 Sept. 4 0 1,000 2,000

Source: California Department of Public Health

Confirmed ICU and non-ICU COVID-19 patients in California hospitals

April 1 June 27 Sept. 22 Dec. 18 March 15 June 10 Sept. 4 0 10,000 20,000

Source: California Department of Public Health

Due to limited testing capacity, not all hospitalized patients with COVID-19 symptoms have been tested. While not all suspected cases will ultimately test positive, including these patients may give a more comprehensive picture of the demands on hospitals. Even with suspected cases included, hospitals have not seen a surge in virus-related patients as feared.

Total confirmed and suspected COVID-19 patients in California hospitals

April 1 June 27 Sept. 22 Dec. 18 March 15 June 10 Sept. 4 0 10,000 20,000

Source: California Department of Public Health

What are the current trends in the Bay Area?

The delta variant has caused a sharp increase in case rates across California. Cases have increased more than fivefold in the Bay Area and statewide since California dropped almost all public health restrictions on June 15. COVID hospitalizations in the state have more than tripled. The Bay Area has relatively high vaccination rates, but the delta variant is spreading rapidly among the unvaccinated, according to county and state data, driving surges across counties. California public health officials have recommended universal masking for state residents in all public indoor settings, regardless of vaccination status, following similar guidance issued by the U.S. Centers for Disease Control a day earlier.

Cases and deaths by Bay Area county

The new case curve represents the 7-day moving average which accounts for variances in daily reporting. The change in new cases compares the number of cases in the past seven days to the previous seven days.

Santa Clara 2,188 135,845 503

Jan. 5 Sept. 5

988 +39% Alameda 1,301 109,944 434 124 +4% Contra Costa 891 90,623 559 1204 +44% San Mateo 666 49,721 171 269 +29% San Francisco 589 47,937 199 281 +25% Solano 300 41,614 302 924 +78% Sonoma 358 37,809 196 455 +50% Marin 243 16,319 35 114 -32% Napa 90 11,760 39 34 -11%
Sources: U.S. Centers for Disease Control and Prevention, the California Department of Public Health and county public health departments, Chronicle / Los Angeles Times data collaboration

The Marin County figures include the San Quentin state prison outbreak that began June 20 and totaled more than 2,200 cases.

Bay Area cases by city or region

Some Bay Area county health departments are now providing details on where people who have tested positive reside, either by region, city or jurisdiction. Use the drop down to search counties (more will be added if data becomes available). Last updated Sept. 1.

Alameda County

Alameda 3,139 441 Albany 435 57 Berkeley 4,517 580 Castro Valley MAC 3,266 420 Dublin 2,304 341 Eden Area MAC 6,905 599 Emeryville 627 105 Fairview MAC 794 82 Fremont 9,457 893 Hayward 15,909 1,433 Livermore 5,552 904 Newark 3,172 235 Oakland 34,325 3,956 Piedmont 233 33 Pleasanton 2,998 402 San Leandro 6,721 689 Santa Rita Jail 265 0 Sunol 42 9 Union City 4,681 425 Unhoused 395 44 Address Unknown 387 23 Under Investigation 767 97 Other 262 49

What is the status of testing in California?

The volume of testing has slowly declined with the increase in vaccinations. Before vaccines were widely available, the World Health Organization had established a recommended positivity rate of 5% for reopening. California was well below that since the end of the winter surge. The state has risen above that marker during the current surge of cases driven by the delta variant.

Daily test results reported in California

July 23 July 30 Aug. 6 Aug. 13 Aug. 20 Aug. 27 Sept. 3 July 23 July 30 Aug. 6 Aug. 13 Aug. 20 Aug. 27 Sept. 3 0 100,000 200,000 300,000 400,000 500,000 7-day average

Positive test rate in California

The positive test rate, or positivity rate, is the percentage of total tests that come back positive each day. A lower positivity rate can indicate that enough tests are being conducted. Read more about the positive test rate here.

July 23 July 30 Aug. 6 Aug. 13 Aug. 20 Aug. 27 Sept. 3 0% 2% 4% 6% 8% 10% 7-day average

Source: California Department of Public Health, Los Angeles Times

Tests are reported by the California Department of Public Health. On April 22, the CDPH began reporting total number of tests conducted, rather than individual people tested, causing test numbers to jump because some individuals are tested more than once.

On July 1, the state reported a backlog of nearly 4,000 positive test results which elevated the positivity rate for that day. This type of variation is accounted for by the trailing seven-day average.

Total cases and deaths in the U.S.

The U.S. has the highest reported total COVID-19 cases of any country. And while California has the highest totals in the nation in terms of cases and deaths, but on a per-capita basis, the total number of cases and deaths is below the national average.

39,945,106 confirmed cases in the U.S. 648,472 deaths

Cases per 100,000 people

1,000 5,000 10,000 15,000+
Sources: The Center for Systems Science and Engineering at Johns Hopkins University, U.S. Census Bureau U.S. reports of COVID-19 are tabulated by Johns Hopkins, which is tracking cases using data collected from the Centers for Disease Control and Prevention and state and local public health departments. Numbers from Johns Hopkins for California may not match the numbers from the top map, which are being compiled by The Chronicle using county reports, county public health departments and Chronicle reporting.

Have more questions?

We’re answering our readers’ most common questions here. Below you can find even more answers for issues specific to the Bay Area.

Where can I get tested?

When and where do I need a mask?

How does the digital vaccine record work?

Should I keep wearing a mask?

What if I don't get the second dose?

How do the vaccines work?

How dangerous is the delta variant?

Will UC system require vaccinations?

When will the pandemic be over?

How will the pandemic be remembered?

Fifth Mission Podcast

Fifth Mission is diving into all the ways COVID-19 is impacting life in the Bay Area. Listen by selecting your preferred podcast service below.

About the data

Update: Cases and deaths data come from files released by the California Department of Public Health, collected from 61 county and city health departments statewide.

Before September 2021, The Chronicle and the Los Angeles Times led a data collection partnership of California media organizations, including the San Diego Union-Tribune, KQED, KPCC, CapRadio, Calmatters and Big Local News at Stanford University.

Data collection at the outset of the pandemic was completed manually, four times each day. This count was able to collect figures far ahead of any state-led tally. Once the state’s data improved, the coalition moved to end its own collection. The source update on Sept. 3 resulted in a one-time change to charts and figures on this page. Questions can be sent to our team here.

Findings signal earlier start to U.S. outbreak: An autopsy report showing that the first death linked to COVID-19 happened Feb. 6 in Santa Clara County and not Feb. 26 in Washington supports research indicating that the outbreak began in the United States much earlier than we knew and before health officials began tracking data.

There were 300 cases reported in the Bay Area when shelter-in-place orders were put in place on March 16. But studies and disease models suggest that more than 10,000 people in the Bay Area likely were infected by then. That research, along with the earlier death identified in Santa Clara County, indicates how far behind the U.S. was in recognizing the outbreak of the virus.