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The change in seasons may or may not affect the spread of COVID-19

CLAIM: The spread of COVID-19 will slow down as the weather warms up.

Unknown. Some viruses vary by season, while others don’t. Even if warmer temperatures and higher humidity affect the spread of the coronavirus, summer weather probably won’t be enough to stop it entirely.

Viruses can be seasonal—or not—for many different reasons

Air temperature and humidity affect how some viruses spread. For example, influenza spreads more quickly in drier and colder conditions. For other viruses, temperature and humidity do not affect disease transmission.

In some cases, a disease’s seasonality may have more to do with changes in human behavior—attending school and spending more time in crowded indoor spaces, for example—than with the weather itself. A virus's spread and impact may also be affected by seasonal changes in people’s immune systems or changes in the number of susceptible people in the population.

It's unclear which, if any, of these reasons will apply in the case of the novel coronavirus.


It’s too early to tell if the novel coronavirus is affected by seasonal changes.

Warmer weather and more humid conditions probably are not enough to stop the spread of COVID-19.

  • There is not yet enough data to know if COVID-19 is seasonal. The studies that have been done so far show the virus can spread in a wide range of weather conditions.
  • Because the virus that causes COVID-19 is new, most people are not immune to it. Even if the virus spreads more slowly in warmer seasons, the large number of susceptible people means the virus can still infect many people.
  • Temperature and humidity vary throughout the year and around the world. If a change in seasons does slow the spread in a particular place, infections can still surge later or in another place.



There’s a lot you can do to slow the spread of COVID-19.

No matter the season, you can take action to protect yourself and others.

  • Handwashing is one of the many important things you can do to stop the spread of COVID-19 and other diseases. Use soap and water and scrub vigorously for 20 seconds.
  • The spread of COVID-19 can be slowed by limiting person-to-person interactions. Avoid close physical contact with other people and stay home if possible.
  • Clean and disinfect frequently touched surfaces daily.


Published on: April 15, 2020