NEW ORLEANS (WGNO) — As winter sets in, the increased prevalence of colds, flu, COVID-19, RSV and other illnesses becomes a familiar concern.
Many wonder why these illnesses seem to flourish during the colder months. The answer lies in the intricate interplay between temperature, humidity and the behavior of viruses.
Temperature and Viral Transmission
Cold weather alone does not cause illnesses, but it does create conditions that favor the spread of viruses.
The National Institutes of Health notes that low temperatures can weaken the immune response in the nasal passages, making individuals more susceptible to viral infections. Additionally, people tend to spend more time indoors during the winter, increasing the likelihood of close contact and transmission.
Viruses Traveling Farther
Viruses, including the flu and SARS-CoV-2 (the virus responsible for COVID-19), are known to travel through respiratory droplets expelled from the body when an infected person talks, coughs or sneezes. In colder temperatures, these droplets can travel farther and remain in the air longer.
The cold air tends to be drier, causing respiratory droplets to evaporate more slowly. This means that virus-containing droplets can linger in the air for extended periods, increasing the risk of exposure for individuals in the vicinity.
Longevity of Viruses in Cold Weather
Research from the NIH indicates that certain respiratory viruses, like the flu virus, may survive better in cold and dry conditions.
Cold temperatures can help the virus’s outer membrane become more stable, allowing it to persist on surfaces for longer periods. This extended viability on surfaces contributes to the ease of transmission through contact with contaminated surfaces.
Humidity’s Role
Humidity levels also play a crucial role in the transmission of respiratory illnesses. According to the CDC, low humidity in winter can dry out the mucous membranes in the respiratory tract, reducing the body’s natural defenses against viruses. Low humidity may also make respiratory droplets smaller, enabling them to stay airborne for longer periods.
The winter months create an environment conducive to the spread of many viral illnesses. Cold temperatures, low humidity and the tendency to spend more time indoors all contribute to the increased transmission of viruses.
Understanding these factors can empower individuals to take appropriate precautions, such as frequent hand washing, wearing masks and practicing social distancing, to lower the risk of getting sick during the winter season.
Stay up to date with the latest news, weather and sports by downloading the WGNO app on the Apple or Google Play stores and by subscribing to the WGNO newsletter.