Watch Covid-19 cases sweep across the United States

Updated 5:46 PM ET, Fri January 14, 2022

(CNN)In 10 seconds, this animation shows the march of Covid-19 cases across the United States in the pandemic's most recent six months.

Starting July 1, 2021, amid a relatively quiet summer the emergence of new cases fueled by the Delta variant spreads across the South in August. Cases then climb across the Plains, Midwest and Northeast by fall.
Another dramatic rise overwhelms the map starting in December, likely attributable to the more transmissible Omicron variant. As of this week, nearly every county is reporting average rates higher than 100 new cases per 100,000 people. Average daily new cases nationwide are now more than three times the pandemic's peak last winter.
The animation is based on county-level data collected by local governments and tracked by the Johns Hopkins University Center for Systems Science and Engineering.
An estimated 64 million cases have been reported in the United States since the pandemic started in 2020, a number that is about 19 percent of the population — though some people have had Covid-19 more than once.
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Data from Johns Hopkins University Center for Systems Science and Engineering each day from July 1, 2021 through January 13, 2022. New cases that are missing or not assigned to a particular county are excluded. Due to reporting anomalies, new case counts are omitted for counties in Nebraska from Sept. 25 to Oct. 1, 2021.
Correction: A previous version of the footnote misstated the year in which the animation ends.