Does cold weather make people sick? Separating myth from fact

This article is up to date as of July 28, 2026, and is based on vaccine guidance provided by the U.S. Centers for Disease Control and Prevention (CDC). Individual states may adopt their own vaccine policies and recommendations based on local public health assessments and regulatory frameworks. For the most up-to-date information, consult your state or a local health department or your health care provider.

People can bundle up, wear fuzzy socks and even sip some tea, but they can still catch a cold. Maybe Jack Frost is to blame, or maybe it's something else altogether. Can cold weather really make people sick?

The answer has more to do with close contact than it does with chilly temperatures. This article helps to separate fact from fiction, explaining why people often feel under the weather during the winter months.

In this article:

Can cold air make people sick?

There's a myth that simply stepping outside in the cold can make someone sick. But it's viruses — not temperature — that can cause illness. Colds can spread at any time of year.

Most respiratory viruses spread through droplets from sneezes and coughs, entering the body when people breathe them in or touch contaminated surfaces and then rub their eyes, mouth or nose. Other respiratory viruses that can cause cold-like symptoms, like influenza (flu) and respiratory syncytial virus (RSV), tend to circulate in winter, so it's understandable that people might associate cold weather with getting sick.

Why do people get sick more often in the winter?

The real reason people tend to get sick with respiratory viruses in the winter has to do with how viruses are transmitted and how people behave during periods of cold weather.

Some viruses may live longer

Some studies mention colder, drier weather as a reason for why there are so many respiratory tract infections in the winter. When temperatures and humidity fall, the virus may be more easily transmitted by droplets.

Researchers have found that colder temperatures may make some viruses' protective outer coatings more durable, helping them survive longer outside the body. Because of this, they can remain infectious in the air or on surfaces for a longer period of time.

Colder, drier air may help some viruses spread

Other studies have shown that colder, drier air may help certain viruses spread between people. When a person exhales virus-containing droplets in a lower-humidity environment, the moisture in those droplets may evaporate quickly. This can shrink them into tiny particles that are small enough to float in the air for a longer time before someone else inhales them.

Being indoors may help viruses spread between people

The good news is that fresh air and cleaner indoor air can help lower the chance of viruses hanging around. Spending time outdoors can help lower the risk of spreading respiratory illnesses because virus particles do not build up in the outdoors as much as they do indoors.

During the months when people spend more time together inside, using an air purifier or filter can help lower exposure to circulating viruses.

5 ways to help reduce chances of getting sick in the winter

The good news is that there are ways to help reduce someone's chances of getting sick, including:

• Getting enough sleep. Most adults may need to get at least seven hours of sleep each night. Getting enough sleep can help with overall health and support the immune system.
• Keeping a distance if people feel sick. Maintaining a distance from others can help lower the risk of spreading a respiratory virus. This includes avoiding close contact with others who are exhibiting cold or flu symptoms.
• Prioritizing good nutrition. The immune system can be supported by eating well. Eating well means emphasizing plenty of dairy products, fruits and vegetables, healthy fats, proteins, and whole grains while limiting added sugars, salt, saturated fats and highly processed foods.
• Staying up to date on vaccines. Getting a flu vaccine each year can help people protect themselves and others from potentially serious flu complications. Some people may also be eligible for vaccines that help protect against other respiratory illnesses, such as respiratory syncytial virus (RSV) and COVID-19. People with questions about these vaccines should talk to a pharmacist or other health care provider for more information.
• Washing hands often with soap and water. Handwashing is important after being in public places, before preparing food and after coughing or sneezing. Good hand hygiene can help prevent the spread of respiratory viruses. A best practice for handwashing is to use soap and water, and to scrub for at least 20 seconds.

Key takeaways

Jack Frost may nip at people’s noses, but viruses are what might make them sick. Viruses may spread more easily in the colder, drier air often experienced winter. In these conditions, viruses spread more easily indoors. That’s why practicing good hygiene and supporting immune health are especially important during the colder months.