(NewsNation) — As of July 8, the Centers for Disease Control and Prevention (CDC) estimated that COVID-19 infections are rising or likely to rise in half the states across the U.S.

According to the agency’s models, the West Coast, Southeast, and Southern regions are leading in the number of increasing cases. However, the CDC notes that, nationwide, the overall level of activity is still regarded as “low.”

The likelihood of the epidemic expanding is particularly high in states such as California, Texas, Louisiana, Mississippi, Alabama, Florida, Kentucky, and Ohio, among others.

The agency’s wastewater monitoring dashboard tells a similar story, with Florida and Alabama leading the country in viral activity levels. Its most recent data comes from the week leading up to July 5.

COVID-19 infections part of summer spike

The uptick is part of a predicted summer spike, which lasts from July to September as part of a twice-a-year pattern recently identified by the CDC. The second spike comes in winter, typically from December to February.

“Our analysis revealed biannual COVID-19 peaks in late summer and winter, a pattern that is expected to persist as long as the rapid evolution of SARS-CoV-2 and cyclical S1 diversity continues,” agency scientists wrote.

A vast majority of the country has seen a “minimal” percentage of patients diagnosed with COVID-19 at emergency department visits in the past week, CDC data shows.

Some states did report a “substantial” percentage change, including New Mexico, Georgia, Kentucky and Virginia.”

‘Razor blade throat’ COVID variant: What to know

The data comes amid reports of a new COVID-19 variant internationally. NB.1.8.1., or “Nimbus,” has been afflicting patients with “razor blade throat.”

The symptom has been identified by doctors in the United Kingdom, India and elsewhere, according to media outlets in those countries.

Airport screening in the United States detected the new variant in travelers arriving from those regions to destinations in California, Washington state, Virginia and New York.

The Associated Press contributed to this report.