Hot Weather Dries Up COVID-19 Droplets, But Virus May Travel Farther in Windy Days

The coronavirus spreads through droplets released by someone who is COVID-19 positive, aside from being cautious about the environment and how far you are from other people, seasonal cycles are also known to play an important role in the transmission of respiratory illnesses.

The role that temperature plays in a pandemic

According to Professor Akiko Iwasaki, an immunobiologist at Yale University, the common cold and flu heighten during winter months. The key outbreaks of SARS-CoV-1 and SARS-CoV-2, the viruses that cause SARS and COVID-19, have happened in winter and they were more difficult to contain.

The connection between viral outbreak and the season has been the topic of numerous studies. According to the review written by Prof. Iwasaki, which appears in the Annual Review of Virology, the two main factors that contribute to the connection are the changes in environmental parameters and human behavior.

This means that the differences in temperature and humidity affect how stable and transmissible viruses are. There are some data reviewed in the new paper that suggest that dry, cold, and unventilated air may contribute to the transmission of influenza in the winter.

Also Read: Elderly COVID-19 Patients May Get Better With Anti-Aging Drugs for 'Younger Immune System'

When people cough or sneeze, a cloud of spray comes out of their mouth or their nose. When the air is dry, the virus in the spray does not swell so it can travel up to six feet, which is the current social distancing recommendation released by the CDC and WHO. This is the reason why people have to stay at least six feet apart, or farther.

However, the exception is if you are outside and the wind is blowing hard, the spray of the virus would travel farther than six feet. If the wind is blowing from your back and toward the person in front of you, the virus might travel up to 10 feet.

Importance of humidity

Humidity increases during spring and summer, so the virus absorbs some of the humidity from the air and swells and may fall to the ground within three feet maximum. People are not as contagious in humid conditions because of this effect.

Health experts also suggested that people should be hydrated, because if you are hydrated, the membranes in your nose are not dried out, thus preventing you from sneezing too much. If the membranes are moist, the virus is less likely to penetrate into the membranes and into the body.

During winter months, the risk is greater in your homes and buildings since the air in the house or buildings is heated, it is dried out. And the relative humidity inside a house or building can be as low as 10% to 20% when it is cold and dry outside. But when it gets warmer and the temperature outside is in the 70s and 80s, the relative humidity in the house or building may be as high as 50% or 60% or even higher.

The changes in temperature can make a massive difference in terms of transmission of the virus. The membranes are more likely to be moist and any virus that is carried from a cough or sneeze would not travel for more than 6 feet.