Where the state’s case rates dropping

California’s new daily COVID-19 cases have been decreasing steadily since mid-August, as a second round of lockdowns was imposed to combat the spike in cases we saw midsummer. The hot spots have also been shifting, and this map shows you how.

To see where the virus is spreading, we calculate the rate of new cases in each county, the number of cases reported in the previous 14 days per 10,000 residents, then track that data over time. The animated map shows how — and when — the coronavirus spread around California from April 1 through Sept. 18.

In early April, the virus was most prevalent in Bay Area and Southern California counties, then became more concentrated in Los Angeles and Imperial counties toward the end of the month, spurred by widespread community transmission. In May, the virus spread farther into the state, as large outbreaks at prisons caused spikes in Santa Barbara, Kings County, and elsewhere.

In June the virus took a stronger hold in many parts of Southern California, following Memorial Day festivities, and increasingly in farmworker communities in the Central Valley. It continued to spread quickly from late June through the middle of July. Then, with new restrictions in place, new cases held steady at around 8,000 daily for nearly two months. Now cases have been on the decline for the past month.

The map suggests California’s early stay-at-home order likely spared the state from the early exponential growth seen in places like Italy and New York. But cases shot up this summer after restrictions eased, then more recently have been decreasing as the clamps went back on. Now we wait to see if new cases will continue to decrease, maintain their current low rate, or start to spike again.