The sting of skepticism when we hear about sniffles or cold symptoms in midsummer. Many of us chalk it up to myth. After all, cold and flu season lives squarely in winter—right? New CDC data shows COVID‑19 is rising across several regions, even as flu and RSV remain remarkably low. Emergency room visits for COVID‑19 are climbing in some parts of the U.S., signaling something worth paying attention to—especially if we’re done worrying about respiratory viruses until October.According to the CDC’s Respiratory Illnesses Data Channel, respiratory illness levels overall are still very low as of August 1, 2025. But the devil’s in the details: COVID‑19 activity is increasing in Mid‑Atlantic, Southeast, Southern, and West Coast states, while flu and RSV cases remain flat or declining. Summer is supposed to be the season of sunshine, vacations, and a break from cold-season sniffles. But this year, something unusual is happening across the United States — COVID-19 is making a comeback, even as other respiratory viruses like influenza and RSV remain uncharacteristically quiet. According to new data from the Centers for Disease Control and Prevention (CDC), emergency room visits due to COVID-19 are up in several parts of the country, especially in Mid-Atlantic, Southeast, Southern, and West Coast states. So what’s going on, and why is COVID spiking in the summer?As of early August, RSV activity is flatlining, and flu levels are decreasing. In contrast, COVID-19 numbers are moving in the opposite direction. Emergency department visits are rising for people of all ages, with particular increases among children under four. According to CDC tracking, while the general level of acute respiratory illness is low overall, the uptick in COVID-19 cases in summer has public health officials paying close attention.The expectation was for COVID-19 to settle into a winter virus pattern. But recent years — including 2024 and now 2025 — have shown that late summer surges are not only possible but are now becoming somewhat predictable.Why COVID Is Spiking When Other Viruses Aren’t?One major reason we see fewer respiratory illnesses in summer is behavior. Warmer weather drives people outdoors, where airflow disperses respiratory droplets and reduces transmission. Windows are open, ventilation is better, and large indoor gatherings are less frequent.However, in parts of the country where temperatures soar into the triple digits, people escape the heat by heading indoors. Air-conditioned environments mean enclosed spaces, close contact, and recirculated air — all of which are ideal for viral transmission.In places like Arizona, summer is our indoor season. And that means more sickness, just like winter on the East Coast.Which COVID Variant Is Behind the Summer Spike?A new COVID-19 variant, known as NB.1.8.1 or "Nimbus," is making the rounds and may be contributing to the current rise in infections. One of the more talked-about symptoms of this variant is an extremely painful sore throat, leading some to nickname it “razor blade throat” COVID.This symptom has been reported in the UK, India, and now parts of the U.S., although overall severity hasn’t shown any dramatic increase. According to the World Health Organization (WHO), the variant is under monitoring but isn’t classified as a variant of concern. Current vaccines remain effective against Nimbus, and there’s no evidence so far that it causes more severe illness than earlier strains.Still, painful symptoms, coupled with the ease of summer spread, are making this version of COVID a hot topic among health experts.Should You Get a COVID Booster Now?Timing matters. According to Dr. Costi Sifri from the University of Virginia Health System, people who are otherwise healthy might benefit from waiting until the fall to get their booster, especially if they're looking to optimize protection for winter gatherings or travel. But if you’ve got a big event coming up — a wedding, trip, or family reunion — a summer booster may offer timely protection.For people in high-risk categories, including older adults and those with compromised immune systems, consulting a healthcare provider about booster timing is critical. The virus may be milder for many people, but it’s far from benign for vulnerable populations.Why Are Kids Contacting COVID Faster in 2025?Last week’s CDC data showed a rise in emergency visits among children under 4 years old. Many of these kids are encountering the virus for the first time, and some may be unvaccinated.Confusingly, U.S. Health Secretary Robert F. Kennedy Jr. recently stated that COVID shots are no longer recommended for healthy children — a move that has sparked concern among pediatricians and public health experts. The American Academy of Pediatrics continues to recommend vaccinations for all children over 6 months old.What Can You Do to Lower Risk?The same principles that applied in previous waves still hold true today. Doctors recommend:Spending time outdoors instead of enclosed indoor spacesWashing hands regularlyWearing masks in crowded areasStaying home if you feel sickAdditionally, consider returning to more mindful health habits — like using HEPA filters indoors, avoiding unnecessary travel if sick, and staying up to date on all your vaccinations, including the flu and COVID.Role of Behavior in Virus SpreadIt's not just biology. Our habits play a huge role in how viruses circulate. When the weather gets unbearable outside, people crowd into movie theaters, gyms, malls, or shared living spaces — all prime environments for transmission. Summer weddings, concerts, and family reunions can also become hotspots.Experts say that if people treated summer with the same level of viral caution they show in winter, spikes like this could be mitigated. But fatigue, misinformation, and the seasonal expectations of carefree health often override the reality of virus behavior.Other Summer Viruses You Should Know AboutWhile COVID-19 is leading the respiratory virus pack this season, it’s not alone. Doctors have also reported increases in:Norovirus (aka the stomach flu)Hand, foot, and mouth disease (common in children, causes rashes and fever)These viruses tend to spread through close contact and poor hygiene, and are particularly active in schools, camps, and daycare centers.The big question now is whether this summer’s spike is a blip or a bellwether. Will we see more off-season waves of COVID-19? Will variants like Nimbus become the norm or remain footnotes in the larger pandemic timeline?While the WHO has designated the public health risk as "low" on a global scale, local surges, particularly among vulnerable populations, demand vigilance. As we approach the fall, new booster recommendations are expected from both U.S. and global health agencies.For now, the take-home message is clear: Don’t let your guard down just because the sun’s out. COVID-19 isn’t taking the summer off, and your health routine shouldn’t either.COVID-19 cases are increasing in several U.S. regions during summer 2025, even as RSV and flu remain low. Experts point to heat-driven indoor activity and the rise of the Nimbus variant as key drivers. Staying alert, practicing basic hygiene, and making informed decisions about vaccination timing remain essential for navigating this unusual respiratory season.