Flu levels are the highest they've been since 2009, the CDC says. The latest on winter illnesses including RSV, COVID-19 and more.

If you feel like you're coming down with something, there's good reason. The hallmarks of the winter season, including lower temperatures, low humidity and indoor heating systems, can create the perfect conditions for viruses to thrive, while leaving our dried-out mucous membranes more vulnerable.

So what can you expect this season? Here’s what the winter forecast looks like for the flu, norovirus, COVID and RSV — and what you can do about these illnesses, according to public health experts.

Click on the links below to jump ahead to each ailment:

• Flu

• Norovirus

• COVID-19

• RSV

Flu

Symptoms

Sore throat, stuffy or runny nose and cough are common symptoms of the flu, as well as many other respiratory viruses. But unlike COVID-19 or a cold, influenza is more likely to hit you all at once rather than to come on gradually.

Current trends

The most recent surveillance data from the Centers for Disease Control and Prevention shows "high" or "very high" flu activity in most of the U.S., with "at least 24 million illnesses, 310,000 hospitalizations and 13,000 deaths from flu so far this season," according to the CDC. These latest numbers suggest that flu levels in the U.S. are the highest they've been since the 2009 swine flu pandemic, CBS News reports.

The winter forecast

The CDC says that influenza activity remains elevated and continues to increase. Flu season typically starts in December, rises significantly in January and February, and then starts to decline in March, “give or take a few weeks,” says Dr. Robert Murphy, professor of infectious diseases at Northwestern University Feinberg School of Medicine.

“We have the peak in the U.S. in late February with influenza,” Dr. David Weber, a professor of medicine at the University of North Carolina at Chapel Hill, tells Yahoo Life. “We can peak as early as November and as late as April or May — but classically, we do peak in late February.”

U.S. public health officials usually look to the Southern Hemisphere (which experiences its winter during our summer) for a preview of what’s to come during our own respiratory virus season. Based on what countries such as Australia and New Zealand saw this year, Dr. Jim Conway, an infectious diseases professor at the University of Wisconsin-Madison, tells Yahoo Life that influenza A, an H3N2 virus, is likely to be the dominant strain this flu season.

Dr. Jessica Justman, a professor of infectious disease at Columbia University, tells Yahoo Life there are usually about 20,000 to 25,000 influenza-related deaths in the U.S. each year, and about 25 to 40 million cases. Last year, there were 31 million cases.

What you can do about it

Anyone older than 6 months is eligible for the influenza vaccine, which can reduce the risk of getting sick by up to 60%. If you do get sick, it can drastically reduce your risk of hospitalization or death. But so far, vaccination rates have been low; the most recent data from the CDC says that 42% of children and 41% of adults have received a flu vaccine this year.

It takes about two weeks after getting the flu shot for your body to produce enough antibodies to be protected, so try to get your shot at least a few weeks before any big travel plans or crowded events where you might be more susceptible to getting sick. And if you’re feeling squeamish about a needle, nasal spray flu vaccines are also an option — though you’ll have to wait until next flu season for the first-ever self-administered nasal spray vaccine to become widely available.

In addition to getting vaccinated, Weber recommends that you remember to keep up healthy habits, even during the busy, indulgent holiday season.

“In the winter months, everyone should try and still get exercise, eat a reasonable, balanced diet with vegetables and fruits and just try and live a healthy lifestyle,” he says.

And if you do get the flu, antivirals such as Tamiflu are available with a prescription. Tamiflu can treat both influenza A and B and shorten symptoms by about 24 hours by blocking the virus from replicating in your body. But you'll need to act fast; antiviral treatments are most effective if taken within the first 48 hours after symptoms begin.

Norovirus

Symptoms

Norovirus, aka “the winter vomiting disease,” is classified by vomiting, diarrhea, nausea and generally feeling awful.

“Norovirus is the leading cause of vomiting and diarrhea from acute gastroenteritis in the U.S., responsible for 58% of foodborne illnesses and about 2,500 outbreaks annually,” Justman says.

“In years when there is a new strain of the virus, there can be 50% more norovirus illness.”

It also spreads unusually easily. Most outbreaks occur through direct contact with an infected person, but it can also live for days or even weeks on surfaces.

Current trends

From Aug. 1, 2024 to Jan. 15, 2025, there were 1,078 norovirus outbreaks reported to the CDC by participating state health departments — nearly double the amount of norovirus outbreaks reported by these states during the same period last season. The latest data shows that the highest spikes in outbreaks occurred in mid-November and mid-December; and while there's been a slight dip as of Jan. 16, the number of outbreaks is still unusually high compared to previous years.

The winter forecast

While you can contract norovirus any time of year, winter is prime time for norovirus and other viruses to spread, as we all gather together indoors.

“The forecast suggests that norovirus activity will continue through the winter, with outbreaks likely peaking in late fall and early spring, which is typical for the virus,” Justman says.

What you can do about it

There’s no vaccine or treatment for norovirus, so you’ll need to lean heavily on prevention. Many of us became hand sanitizer junkies during the COVID-19 pandemic, but experts say the key to norovirus prevention is good old-fashioned hand-washing.

“The tricky part about norovirus is that for people that have adopted alcohol-based hand gel as their primary way of cleaning their hands, norovirus is basically immune to those,” Conway says. “So when diarrhea outbreaks happen, we really do encourage people to go back to soap and water.”

If you do get sick, drink plenty of fluids (especially liquids with electrolytes), get plenty of rest and only eat soft, bland foods.

COVID-19

Symptoms

Respiratory illnesses like COVID-19 share many common symptoms, such as cough, shortness of breath, fever, achiness, congestion and sore throat. One telltale sign that sets COVID apart is loss of taste or smell, which isn’t common with other respiratory diseases. Symptoms of COVID may also start out mild and then gradually become more severe.

Current trends

COVID tracking has evolved a lot over the past four years. Fewer people are testing and reporting the results to a health care provider, so most cases tracked come from wastewater surveillance and emergency department visits.

In the past week, the percentage of emergency department visits with diagnosed COVID-19 was "minimal" or "low," according to the most recent CDC data. Deaths from COVID have been declining after a small peak in early January, with 398 weekly deaths reported in the first week of February — considerably less than the 1,744 COVID deaths reported in the same week last year.

The most prevalent COVID variants currently circulating are Omicron XEC (accounting for 47% of cases), Omicron LP.8.1 (accounting for 15% of cases) and KP.3.1.1 (accounting for 14% of cases), according to the latest CDC data.

The winter forecast

Predictions for COVID-19 are more difficult to pin down because it’s a newer virus than RSV or influenza, which experts have years of experience tracking. COVID has also defied some of the usual seasonal patterns of other respiratory viruses. COVID appears to be behaving as we've seen over the last three years, with two peaks — one during the summer and another during the winter.

So far, this COVID winter peak has been less than what we saw in 2024. In December, Murphy (of Northwestern University) told Yahoo Life that deaths from COVID-19 were “hovering between 50 to 60 per day for the past several weeks” — down from around 200 per day in 2023.

What you can do about it

Anyone 6 months and older is eligible for an updated COVID-19 vaccine, which, like the flu shot, is reformulated each year to better match circulating variants. Experts say that groups such as the elderly, pregnant women, people with preexisting conditions and the immunocompromised are particularly susceptible to complications from the virus and are strongly encouraged to get vaccinated. So far, COVID-19 vaccination rates have been low, with 20.9% of adults reporting they’ve received the vaccine (and 10% of children), according to the latest CDC data.

Weber says that you should consider reviving an old pandemic-era habit and mask up, particularly during holiday travel in crowded places and especially if you’re vulnerable or will be around people who are.

If you do get sick, antiviral treatments such as Paxlovid are available to reduce your risk of ending up in the hospital or dying. Weber says such treatments need to be started within five days of the onset of symptoms to be effective. Free at-home COVID tests (you can order yours here) are also available to help you determine if your symptoms are from COVID-19 or from something else.

RSV

Symptoms

Symptoms of respiratory syncytial virus, or RSV, may start off similar to a common cold, with sneezing and a runny nose. But a “barking or wheezing cough” may be your sign that it has progressed to something more serious.

Current trends

The most recent trends show that RSV levels rose and peaked in December and have started to decrease since January. Justman told Yahoo Life in December that RSV activity in the U.S. was elevated, especially in the Southeast and especially among children, but that the surge was expected for this time of year.

The winter forecast

RSV season typically starts in the fall, from mid-September to mid-November, and peaks in the winter from December to mid-February. The CDC is forecasting that this RSV season is likely to “follow established trends,” Justman says.

“We can expect the peak in hospitalizations to align with typical seasonal patterns, with a weekly hospitalization rate similar to or lower than the 2023-2024 season’s peak — which was 4.2 weekly laboratory-confirmed hospitalizations per 100,000,” she says.

What you can do about it

The RSV vaccine is recommended for everyone over age 75, and for any individuals of ages 60 to 74 who have underlying health conditions. It’s also available to pregnant women between weeks 32 and 36 of pregnancy as a means of protecting the baby from RSV for the first few months of life. RSV antibodies can also be given to babies before they’re 8 months old to help protect against severe RSV illness.

“We have found that RSV affects young babies and the elderly pretty significantly, and RSV is almost as big a problem as influenza,” Conway says. “If you're in a high-risk population or if you're a person that has always been told you're at high risk for COVID or for influenza, you should really think about RSV as well.”

Weber says that as of Nov. 4, 40% of adults over age 75 and 32% of adults ages 60 to 74 who are at increased risk for RSV had gotten the RSV vaccine.

There aren’t any antivirals for RSV, so the CDC recommends that you manage symptoms at home with over-the-counter fever reducers and pain relievers along with lots of fluids, and to contact a health care provider if you have difficulty breathing or if symptoms worsen.