COVID-19 Cases Growing in All 50 States as 'Nimbus' Variant Drives Late-Summer Surge Nationwide

COVID-19 infections are growing or likely growing in all 50 states, according to the latest estimates from the Centers for Disease Control and Prevention, marking a dramatic nationwide expansion of the virus's seasonal summer wave just as students return to school and Americans wrap up summer travel.

As of Aug. 12, 2026, the CDC's Current Epidemic Trends model estimated that COVID-19 infections were growing or likely growing in 50 states and declining or likely declining in zero states, with the agency reporting no estimate available for Iowa due to insufficient data. According to the CDC's own modeling summary, that leaves the entire country, apart from Iowa's data gap, showing an upward trajectory in transmission for the first time this summer.

The shift represents a striking reversal from conditions just weeks earlier. According to Newsweek, on July 22 the CDC had estimated infections were growing or likely growing in only 37 states, with 11 states showing little change in transmission at the time. By mid-August, those stable pockets had disappeared entirely from the map, with 47 states now classified as "Growing" and New Hampshire, Rhode Island and the District of Columbia categorized as "Likely Growing." In many states, the CDC estimates there is greater than a 99% probability that infections are actively increasing.

The reversal is even more pronounced compared with earlier this summer. According to a report from Political.org, the CDC had estimated infections were declining or likely declining in 41 states, with growth seen in just one state, as recently as June 2. The speed of that turnaround reflects a now-familiar seasonal pattern public health officials have observed for several consecutive years.

Andrew Pekosz, a professor of molecular microbiology and immunology at Johns Hopkins Bloomberg School of Public Health, described the current surge as consistent with an established late-summer pattern. "This looks like a pattern that has been documented in the past few years," Pekosz told Newsweek, referring to the recurring late-summer and early-fall increase in COVID-19 transmission the country has experienced in recent years.

Dr. John Brooks, an infectious disease physician at Emory University in Atlanta who previously worked at the CDC, offered a similar assessment while acknowledging the psychological gap between public perception and current data. "I think most of us kind of feel like it's fading away and are certainly very grateful for that," Brooks said. "But nationally we're seeing it ticking up pretty much everywhere."

Wastewater surveillance data has provided further confirmation of the trend's scale. Amanda Bidwell, scientific program manager for WastewaterSCAN, told Today.com that viral concentrations detected in wastewater samples have risen sharply this month. "So far in August, SARS-CoV-2 concentrations are up 106% compared to July 2026," Bidwell said, adding that the West and South currently show the highest concentrations nationally.

Despite the widespread geographic growth, health officials have emphasized that overall COVID-19 activity remains comparatively low and that the surge has not translated into a significant strain on hospitals. According to the CDC, as of Aug. 14, the amount of acute respiratory illness prompting people to seek medical care remains very low overall, even as COVID-19 activity specifically is increasing in the West and South. Emergency department visits tied to COVID-19 have similarly remained low, according to multiple outlets citing CDC data.

Dr. Patrick Koo, division chief of pulmonology and critical care at Erlanger Hospital, said fewer patients are seeking emergency care for COVID-19 compared with earlier phases of the pandemic, attributing the shift both to the virus's evolution and to more people managing mild illness at home. "The virus has, of course, gone through multiple passes and mutations, and therefore the symptoms of COVID-19 are now much much milder compared to what we saw during the pandemic, so I think that if we take proper precautions and you know try to practice good hand hygiene to stay away from others that are sick for until they get better, of course, and that would minimize a lot of the transmission," Koo said. He added that current seasonal patterns should not cause alarm. "We do see periodic rises in certain months usually in the summer and then also in the winter as well so and so I think that there's no there's nothing to be alarmed about COVID-19 right now," Koo said.

The current wave has been driven primarily by a variant known as NB.1.8.1, commonly referred to as "Nimbus," a descendant of the JN.1 Omicron lineage that had already accounted for an estimated 43% of circulating cases by late June, according to Political.org's reporting. Separately, a more heavily mutated strain known as BA.3.2, nicknamed "Cicada," has been spreading globally since emerging earlier this year, though it has not gained significant traction within the United States. According to Today.com, roughly 15% of current U.S. cases are attributed to the Cicada variant, even as no major new mutation has driven the current wave beyond the continued spread of Nimbus.

Public health researchers have noted that COVID-19's biannual surge pattern, occurring in both summer and winter, remains distinct from more familiar seasonal illnesses such as influenza, which typically peaks only during colder months. The precise biological reason behind COVID-19's dual seasonality remains unclear, according to reporting from Political.org, though experts have pointed to a combination of factors, including waning immunity following winter infections, increased indoor gatherings in air-conditioned spaces during hot summer months, and continued summer travel patterns, as likely contributors to the recurring late-July and August peaks the country has now experienced for three consecutive years.

Symptoms associated with the current wave remain broadly consistent with those seen in earlier omicron-lineage variants, typically appearing within two to 14 days of exposure. According to the CDC, common symptoms continue to include fever, cough, fatigue, congestion, sore throat, and loss of taste or smell, among other cold- and flu-like signs.

As students return to classrooms and colder weather approaches in the coming months, health officials are likely to continue monitoring whether the current nationwide growth trend persists, plateaus or begins to recede, following the pattern of prior late-summer surges. This story includes information on a virus that can pose greater risk to certain populations. If you are concerned about COVID-19 symptoms or exposure, particularly if you are immunocompromised, elderly or otherwise at higher risk, consult a health care provider for personalized guidance.