How Could Winter Affect The Spread of COVID‑19?

by Kroger Health Staff

Last Updated: December 7, 2020

Winter’s cold, wet weather will soon drive Americans indoors. Medical experts are concerned that COVID-19 could spread more easily in winter months like other viruses, including influenza and the common cold. Scientists are concerned two factors – humidity and human behavior – could influence COVID-19 infections during the next few months.

According to the World Health Organization, there is no evidence that cold weather kills viruses like COVID-19. However, the cold weather means we are spending more time interacting indoors, and most of the COVID-19 transmission occurs indoors, so infections are expected to rise in the colder months. In addition, some studies have linked cold, dry conditions with outbreaks of the disease.

The concern is that people will mingle more closely inside, and that the air they breathe will make the virus more dangerous, especially in rooms without proper ventilation. The Centers for Disease Control and Prevention (CDC) recently updated its guidance to acknowledge Coronavirus might be adrift in indoor air. In addition, humidity is a key factor in the spread of viruses in the winter. In winter we heat our air, which lowers the humidity indoors. COVID-19 spreads more easily when the air is dry, so it is important to keep indoor rooms at a healthy relative humidity by using a humidifier when needed. Humidity can also influence our body’s ability to fight infection. The first line of defense in the lungs relies on mucous’ combined effect in the respiratory tract and the upward beating of the hair-like cilia on lung cells. The mucous is sticky and catches particles, including viruses, before they can infect the lungs. In dry air, there is less mucous. In warmer weather, relative humidity is usually between 40% - 60%. Studies show more infections occur and spread when the relative humidity falls to 20% and below.

Another consideration for COVID-19 is that influenza infections are expected to increase in the winter months. Flu season typically occurs between October and May, though flu can occur anytime throughout the year. If the flu season is severe, it could overwhelm the healthcare system. If you haven’t done so already, it is important to get a flu shot to protect yourself and others from the flu. The CDC recommends everyone 6 months and older receives a flu shot. To schedule an appointment at your local Kroger Health Pharmacy or Clinic. Our team of caring and expert healthcare professionals can take care of your flu shot needs and address any questions or concerns you may have.

While the world anxiously awaits a life-saving vaccine to help prevent the spread of the virus this winter, we all need to follow CDC guidelines and wear a mask, keep a social distance and wash our hands frequently.

Disclaimer: The information in this story is accurate as of its publication. However, the situation surrounding COVID-19 is ever-evolving. We are working to keep our stories up-to-date as changes occur, but we also encourage everyone to check news and recommendations from the CDC, WHO, and their local authorities.