COVID Cases Are Rising Across the US in a Summer Surge

<><><>As August ends, a nationwide COVID-19 summer surge is actively driving up infections across the United States from a low baseline, according to health experts. Data from the Centers for Disease Control and Prevention indicates that infections are growing or likely growing in 47 states, with the highest levels currently concentrated across the South and the West.

According to Dr. Syra Madad, an infectious disease epidemiologist at Harvard’s Belfer Center and chief biopreparedness officer for New York City’s public hospitals, the upward trend became apparent across parts of the South and West during July before clearing showing nationwide growth by late July and early August. Wastewater monitoring data from Stanford University-led WastewaterSCAN shows that coronavirus concentrations doubled each month since June, placing August levels up 105% compared to July.

Tracking Wastewater Trends and Seasonal Waves

While wastewater concentrations remain lower overall than they were at this same time last year, testing sites are trending upward nationwide. Amanda Bidwell, scientific program manager for WastewaterSCAN, noted that virus concentrations in the West and South have already surpassed the levels observed during the previous winter peak.

Unlike traditional respiratory illnesses such as influenza and RSV that typically confine themselves to a single winter season, COVID-19 has established a predictable pattern of rising twice a year during both summer and winter months. Data from the CDC’s COVID-NET hospital tracking dashboard shows a consistent uptick in cases starting every July and running through September.

If you actually look at it, it starts year after year at a national level. It’s been practically identical, Dr. Michael Mina, chief medical officer at Invivyd and a former assistant professor at the Harvard T.H. Chan School of Public Health, told USA TODAY. Sometime in early July, or mid-July, you start to see an upswing, and then it really picks up speed.

Understanding the Drivers Behind the Summer Surge

Experts point to a combination of behavioral and environmental factors to explain the recurring summer wave. According to Mina, human contact rates remain remarkably consistent across years, but environmental pressures shift how people interact. During intense summer heat, populations in warm regions frequently move indoors into air-conditioned spaces with closed windows and limited ventilation, which facilitates viral transmission.

As the summer season transitions into late August and September, upcoming changes in daily routines—including children returning to school—introduce new patterns of social contact that can circulate pathogens within households and communities. Once the fall arrives, a brief epidemiological lull often follows as these specific seasonal contact vectors temporarily shift.