San Francisco County

0.88 million inhabitants of San Francisco counties

Q1: Is an outbreak starting?

If the rate of new cases is growing (above 0%) that is not good (exponential growth bad).

Growth/Shrinking of Rate of New Cases ^*

* Rate of new cases is weekly, but change % is quoted in terms of daily growth/shrinking.

Q2: How dangerous is it now?

See a historical perspective for broader context.

New Covid deaths ^* per week per million in San Francisco Metro Area

* What is counted as a death from COVID-19?
** TB = Tuberculosis. Historical rates are age-adjusted. 1865 rate is based on limited records, but follows the historical trend.

Q3: Does the CDC say I should wear a mask indoors in public?

Guidance from the CDC (as of July 27 2021) for vaccinated people is: “wear a mask indoors in public if you are in an area of substantial or high transmission.”

The CDC uses two indicators to determine level of transmission:

1. weekly cases per population
2. percentage of positive diagnostic and screening nucleic acid amplification tests

More more than 500 new cases per week per million persons, is substantial or high transmission per the CDC. For more details see CDC COVID Data Tracker.

New Covid cases per week per million in San Francisco Metro Area

Further Details

New cases per week:

New cases per day:

New deaths per week:

New deaths per day:

Data check

Population = 881,549