Another month, another phase of the pandemic — and a new state “blueprint” for a phased economic reopening in California.
We’re tracking how the Bay Area’s nine counties are progressing through the new system announced by Gov. Gavin Newsom on Aug. 28.
To sum it up: There are four tiers — ranging from widespread to moderate — with corresponding colors (purple, red, orange, yellow) and two all-determinative metrics: the per-capita case rate and the positivity rate for PCR tests, both averaged over seven days. A third figure — the number of tests per-capita — can lower a county’s case rate in the state’s formula from between 12% and 40%. The state will update its figures every Tuesday, starting Sept. 8, and a county must meet both marks for 14 days before it is eligible to move to the next tier.
Read more about the new plan — and what it means for restaurants, offices, schools and more — here.
San Francisco and Napa were the Bay Area’s only counties in the second tier, otherwise known as substantial or red, with limited-capacity reopening permitted in many sectors (but local stricter orders still enforced), when Newsom announced the initial tiers. Everywhere else was, like much of the state, in Tier 1, known as widespread or purple, with many sectors of their economies shut down or severely limited.
As of Friday, Sept. 4, San Francisco, Napa and Santa Clara counties meet both thresholds for tier two, according to our data. Alameda and San Mateo counties were also trending toward tier two. All but San Mateo have also tested enough for an adjustment to kick in and lower their case rates, while none of the counties in the first tier have tested enough for it to apply.
In the last official update from the state, 38 of its 58 counties — including all of Southern California but San Diego and all of the Bay Area except San Francisco and Napa — were in Tier 1. Nine counties, including the aforementioned three, were in Tier 2, another nine were in Tier 3, and two remote mountain counties — Alpine and Modoc — were in the lowest of the four tiers.
Note: CDPH dates cases to its earliest known infection and uses a seven-day lag, while this news organization tracks them in real-time when they are reported by the county health department. CDPH also separates inmate populations, while this news organization does not, leading to higher rates represented here in Marin County than in CDPH data because of San Quentin State Prison.
Case rate adjustment multiplier: < 2.4 tests/1,000 population = no adjustment; 2.41-2.99 = 0.88; 3-3.59=0.78; 3.6-4.19=0.71; 4.2-4.79=0.65; > 4.8 = 0.6
Alameda
Cases per 100,000 per day (past 7 days): 10.4
Tests per 1,000 per day (past 7 days): 3.2
Case rate adjustment multiplier: 0.78
Adjusted per-capita case rate: 8.1
Positivity rate: 3.3%
Contra Costa
Cases per 100,000 per day (past 7 days): 10.0
Tests per 1,000 per day (past 7 days): 1.6
Case rate adjustment multiplier: n/a
Adjusted per-capita case rate: 10.0
Positivity rate: 6.3%
Marin
Cases per 100,000 per day (past 7 days): 12.7
Tests per 1,000 per day (past 7 days): 1.9
Case rate adjustment multiplier: n/a
Adjusted per-capita case rate: 12.7
Positivity rate: 6.7%
Napa
Cases per 100,000 per day (past 7 days): 6.4
Tests per 1,000 per day (past 7 days): 3.7
Case rate adjustment multiplier: 0.71
Adjusted per-capita case rate: 4.6
Positivity rate: 1.7%
San Francisco
Cases per 100,000 per day (past 7 days): 8.8
Tests per 1,000 per day (past 7 days): 4.6
Case rate adjustment multiplier: 0.65
Adjusted per-capita case rate: 5.7
Positivity rate: 1.9%
San Mateo
Cases per 100,000 per day (past 7 days): 8.8
Tests per 1,000 per day (past 7 days): 1.4
Case rate adjustment multiplier: n/a
Adjusted per-capita case rate: 8.8
Positivity rate: 7.0%
Santa Clara
Cases per 100,000 per day (past 7 days): 10.1
Tests per 1,000 per day (past 7 days): 4.5
Case rate adjustment multiplier: 0.65
Adjusted per-capita case rate: 6.5
Positivity rate: 2.7%
Solano
Cases per 100,000 per day (past 7 days): 9.7
Tests per 1,000 per day (past 7 days): 1.5
Case rate adjustment multiplier: n/a
Adjusted per-capita case rate: 9.7
Positivity rate: 6.4%
Sonoma
Cases per 100,000 per day (past 7 days): 18.6
Tests per 1,000 per day (past 7 days): 1.8
Case rate adjustment multiplier: n/a
Adjusted per-capita case rate: 18.6
Positivity rate: 10.3%
