How Coronavirus Has Spread Across the United States: Track the ‘Eye of the Epidemic’

For months now, many have been baffled by how the United States, among the richest and most technologically capable countries on Earth, could lead the world in both confirmed cases of COVID-19 and resulting deaths. Fingers have been pointed in many directions, from listless political leadership to intractable cultural attitudes. But there is another factor that arguably made the U.S. a sitting duck for viral catastrophe: the country’s 328 million residents are scattered across its many states, districts and territories, each with their own approach to viral containment. We aren’t battling one epidemic—we’re battling more than 50 of them.

More than one observer has compared the country’s battle against the coronavirus to a game of Whack-a-Mole—every time the curve appears to flatten in one state, it arcs in others, like a hurricane with no sense of direction or fatigue. To visualize this phenomenon geographically, TIME traced the wandering eye of this infectious storm by calculating, for each day back to late February, the epidemic’s midpoint—the precise location in the U.S. from which half of all new reported cases were to the west and half were to the east, and likewise for the north and south (what demographers call the median center of population). This feature will update daily. Here’s what it currently looks like:

As expected, the domestic trajectory of Hurricane COVID begins in the upper Northwest. That’s where the first confirmed U.S. case was reported, on Jan. 20 in Snohomish County, Wash., just a few weeks after the virus emerged in Wuhan, China. After a period of relatively slow growth in February, the “eye” begins its push south into California, weeks before the Grand Princess docked in the Port of Oakland on March 9 with 103 infected passengers aboard.

At the same time, cases were growing rapidly in the tri-state area of New York, New Jersey and Connecticut, likely after travelers brought the disease there from Europe, opening a second theater of combat. “The virus had begun multiple assaults into the U.S.,” as two of my colleagues wrote of these spikes on opposite coasts. While the rate of new cases in the west began to stabilize, the tightly-packed areas around New York City experienced surges that rapidly drew the eye of the COVID hurricane across the country.

The eye then hovered around the New York region until mid-April. It’s remarkable to see the median longitude (the vertical line) so close to this hotspot, as it means that, on many days, the tri-state area essentially had as many new cases as the entire rest of the nation to the west and south.

Next, a surge in and around Chicago, combined with an eventual flattening of the curve in New York, drew the line west through mid-May, when a precipitous spike in Los Angeles began to tug the median latitude southward. By this time, some states, like Virginia, were beginning to ponder a tempered reopening of public spaces like beaches and parks by Memorial Day.

Come June, many regions in the south that had not yet seen the worst of the pandemic began reopening—in retrospect, prematurely. Soon, Texas, Arizona and Florida were the new hotspots, drawing the center south and west as Southern California also continued to suffer. In late June through mid-July, the eye was caught in a tug-of-war centered in Arkansas amid rising cases in the Carolinas. Recently, surges in cases in Iowa and the Dakotas and drawing the center northward once again.

It’s important to note that the location of our center point does not illustrate a surge of cases in that particular spot. Instead, it’s the theoretical halfway point that evenly divides the total number of new infections in both directions. Arkansas, for example, was relatively stable when it represented the geographic center of the epidemic, reporting an average of about 20 cases per 100,000 residents a day, significantly lower than several neighboring states.

Now, with COVID-19 on the decline across much of the deep south, the eye is heading back north, inching through the Heartland as cases rise in parts of the midwest through central Illinois. Where the eye eventually settles, however, is far less relevant than the still-distant hope that the virus stops spreading altogether.

Last updated: December 1, 2020 at 10:23 p.m.