After months of steady decline, COVID-19 cases in the U.S. have begun to rise again—and no, it’s not an anomaly. This marks the anticipated beginning of a summer surge, with public health data underscoring how the virus behaves with seasonal rhythms—even while national activity levels remain low.The Centers for Disease Control and Prevention now reports that infections are climbing in approximately half of all states, particularly throughout the Southeast, South, and the West Coast—California included. CDC’s national wastewater surveillance, which gauges virus circulation in sewage, has shifted from “very low” to “medium” activity, confirming increasing spread. In California, the WastewaterSCAN program showed the virus present at 95% of monitored sites, with concentration levels rising steadily since June. While this escalation mirrors trends from previous summers, the data make it clear: COVID is here once again. California isn’t just another dot on the map—it’s a bellwether. With 150 COVID-related deaths per week across the U.S., even a modest surge in California can impact national outcomes. Moreover, its key role in travel, entertainment, and indoor-heavy lifestyles during heatwaves elevates the risk of amplification.This is not a sharp spike, but a gradual climb, close to last year’s levels. That similarity should not breed complacency; rather, it offers an early chance to act. The Rise of NB.1.8.1 (“Nimbus”) and Other VariantsWastewater sequencing in California shows:LP.8.1 dominating with 33.2% of samplesXFG at 24.6%NB.1.8.1, better known as “Nimbus” or the “razor‑blade throat” variant, accounting for 7.5% Though nicknames highlight painful throat symptoms, there's no current evidence that Nimbus causes more severe illness or hospitalizations. Still, its growing prevalence and transmissibility mean health officials are tracking it closely.CDC analysis reveals that COVID now follows a twice-yearly pattern—with surges in both summer (July–September) and winter (December–February) San Francisco Chronicle. Researchers attribute this cycle to genetic changes in the virus’s spike protein, particularly the S1 region, which enhances viral binding and transmission.History confirms this: California typically peaks in mid-July to late August—making current trends both expected and potentially warning signs of a broader wave. Who’s at Risk and What You Can Do?While activity levels are officially “low”, complacency isn’t wise—especially for high-risk groups: adults over 65, immunocompromised individuals, pregnant people, and infants under 2:Ensure vaccination within the past year or seek boostersTest if experiencing symptomsWear masks in crowded or high-risk indoor spacesAs Dr. Peter Chin‑Hong of UCSF advises, “For those older than 65, very immunocompromised, pregnant persons and infants—especially under 2—I would make sure you have received a COVID vaccine at least in the past year.”Emergency department visits for COVID remain low nationally, though recent upticks have occurred in the Pacific Northwest and Southeast—the highest since early spring. Notably, this summer rise coincides with a surge in Parvovirus B19, which poses risks for pregnant women and is prompting additional caution.COVID hospitalizations have become more predictable with seasonal waves, but still linger above zero year-round, reinforcing the need for vigilance .The recurring summer pattern suggests that COVID-19 is shifting from pandemic unpredictability to endemic regularity, but that doesn’t diminish its impact. Continued mutation, waning immunity, and seasonal behaviors (like travel and indoor gatherings) ensure that vigilance remains essential.As the CDC and WHO emphasize, updating vaccines, using masks in crowded environments, testing when sick, and keeping track of local wastewater trends are practical steps everyone can take.California’s rise in COVID cases—though still within low national activity—matters. It signals seasonal resurgence and underscores ongoing viral evolution through new variants like Nimbus. Protecting public health requires action: vaccination, testing, masking, and staying informed about evolving trends.The summer wave is predictable—but entirely preventable in its impact. With timely measures, we can ride it out safely.