Can You Get the Flu in Summer?

Summer is usually associated with fun in the sun, beach trips, and no school. But along with the warmer weather comes questions about illnesses like the flu. Typically, flu season happens in the fall and winter. But is it possible to get sick with influenza during the summer months?

What Is the Flu?

The flu, short for influenza, is a contagious respiratory illness caused by influenza viruses. There are four types of flu viruses: A, B, C, and D. Human influenza A and B cause seasonal flu epidemics almost every winter in the United States.

Influenza can cause mild to severe illness. Common symptoms include fever, chills, cough, sore throat, runny/stuffy nose, muscle/body aches, headaches, fatigue, and sometimes vomiting and diarrhea.

How Does the Flu Spread?

The flu spreads mainly through droplets produced when someone infected with influenza coughs, sneezes, or talks. These droplets can land in the mouths or noses of others nearby. A person may also get flu by touching a surface that has flu virus on it and then touching their own eyes, nose, or mouth.

People with flu are most contagious in the first 3-4 days after getting sick. Adults can spread the virus to others beginning 1 day before symptoms start and up to 5-7 days after.

Flu Activity Peaks in the Winter

In the United States, flu viruses start circulating in the fall and peak between December and February. The reason flu activity increases in the winter is not completely clear but likely involves several factors:

Lower humidity – The flu virus survives better in dry air, which is more common in the winter. The mucus membranes of the nose and throat also lose moisture in dry air, which can make them more vulnerable to viral infection.
People stay indoors more – Spending more time indoors during the winter means people are in closer contact, increasing the risk of spreading the flu virus.
Weakened immune systems – Less sun exposure in the winter can lead to low vitamin D levels which may weaken immunity. Fatigue from seasonal allergies also stresses the immune system.
Changes in the respiratory tract – Cold air may cause nasal passages to narrow which can slow down the natural cleaning of viruses and bacteria.
Flu loves the cold! – Influenza viruses themselves are most stable in colder temperatures and thus transmit best in winter conditions.

Can You Get the Flu in the Summer?

So during warm summer months, does the flu virus take a vacation too? Well, not exactly. Although flu activity usually drops to low levels, it is still possible to get sick with the flu when it’s hot out.

Every year there are some flu cases that happen outside of the typical fall-to-winter influenza season. For example, the flu may circulate at summer camps or on cruise ships when people are in close contact. The Southern Hemisphere, which has its winter during our summer months, will have its annual flu season June-August and can spread the virus worldwide.

The 2009 H1N1 “swine flu” pandemic predominantly affected children and young adults in the spring and summer months. When new influenza strains emerge, they can circulate outside of normal patterns.

In general though, flu rates are quite low in the summer. One study showed an average of 300 flu cases per 100,000 people during peak months versus 19 per 100,000 during summer months.

Who Is Most at Risk for Summer Flu?

Although less common, the people most vulnerable to flu infection in the summer are similar to the winter months. Those at highest risk include:

Young children, especially infants and toddlers
Adults 65 years of age or older
Pregnant women
Residents of nursing homes or long-term care facilities
People with chronic conditions like asthma, heart disease, diabetes, kidney disease, and HIV/AIDS
People with weakened immune systems due to disease or medication such as chemotherapy or steroids

Summer Flu Prevention Tips

To reduce your chances of getting the flu during the summer:

Get the flu vaccine – This offers protection against current circulating strains. Experts recommend vaccination by late October but getting it in summer is shown to protect people through the holidays.
Wash hands frequently – Clean hands with soap and water regularly, especially after coughing or sneezing. Alcohol-based hand sanitizer is a good option when soap is unavailable.
Practice good hygiene habits – Avoid touching your eyes, nose, and mouth since these are entry points for germs. Cough or sneeze into a tissue or your elbow rather than hands. Disinfect commonly touched surfaces such as counters, doorknobs, and keyboards.
Stay home when sick – Stay home from work, camp, or social gatherings if you have flu symptoms to prevent spreading it further.
Live a healthy lifestyle – Eat a balanced diet, exercise regularly, manage stress levels, and get sufficient sleep. This will help keep your immune system strong against infections.

Flu Symptoms in Summer vs. Winter

The signs and symptoms of influenza infection are similar whether you get it in July or January. Typical flu indicators include:

Fever and chills
Cough, sore throat, and nasal congestion
Muscle and body aches
Headaches and fatigue
Vomiting and diarrhea (more common in children)

In summer months, the flu is likely to be mistaken for heat exhaustion or food poisoning since fever and body aches occur in these conditions too. Stomach flu viruses like norovirus also have overlapping symptoms with influenza.

Testing may be needed to confirm the flu since many summer illnesses can imitate it. See your doctor if signs persist more than a few days or worsen.

Conclusion

To summarize, while flu activity peaks in the colder months, influenza viruses can still spread and cause infection in the summer too. Less cases occur from June through September compared to the winter flu season. But cruises, camps, travel, and close contact make illness possible. Similar viruses like stomach bugs or COVID-19 may also be mistaken for the flu. Getting vaccinated before the fall and practicing healthy habits can help decrease your risk of the flu, even during the dog days of summer.

FAQs About Summer Flu

Can I get a summer flu from being in the heat too long?

No, the viruses that cause “summer flu” are not actually related to heat exhaustion, sun stroke, or overheating. True influenza comes from person-to-person transmission, not from hot summer conditions.

What’s the difference between the stomach flu and influenza?

The stomach flu describes gastrointestinal illnesses like norovirus and rotavirus. Flu refers specifically to respiratory infections caused by influenza viruses. Vomiting can occur with the flu but the main symptoms are fever, body aches, and cough.

Can I get the flu from swimming in a public pool?

It’s unlikely. Influenza viruses are spread through respiratory droplets, not chlorinated pool water. However, crowded pools may bring you into close contact with someone who is contagious.

Is flu more or less serious if you get it in the summer rather than winter?

Season does not change the severity of actual influenza infection. Complications like pneumonia are possible year-round. However, other viruses causing “summer flu” symptoms are generally milder than true influenza.

How long does summer flu usually last?

Just like seasonal flu, summer influenza typically lasts 1-2 weeks but cough and fatigue can persist longer. With plenty of rest and fluids most healthy people will recover within 7-10 days.