A new study released in June 2021 by Yale University shows how weather impacts the spread of COVID-19. The findings show what time of year the virus thrives and what parts of the country are more at risk because of their climate. 


What You Need To Know

  • The reproductive role of weather in COVID-19 is almost 18%

  • Humidity, temperatures and sunshine were the main weather factors that impact the virus

  • Temperatures above 68 degrees inhibit the spread of COVID-19

The Yale School of Public Health studied weather and COVID-19 cases from March 2020 to December 2020 in the United States. Their goal was to see the effect of weather factors in the spread of the coronavirus. This study broke new ground and corrects previous findings in other studies from early in the pandemic.

The study focused on three main weather factors. 

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Heat, humidity and UV rays, which is essentially sunshine, were found to have notable impacts on the coronavirus's rate of reproduction. Overall, weather accounted for 17.5% of how well the virus can multiply. The scientists at Yale say that weather is a significant factor but that vaccines, masks and distancing have bigger contributions to how fast the virus breeds. 

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Humidity was the weather condition that had the biggest impact on the virus's reproduction.

Here's the breakdown:

  • Temperature: 3.73%
  • UV radiation: 4.44%
  • Humidity: 9.35%

This information led the scientists to conclude that the virus replicates at a faster rate in regions where the weather is cool and dry and has low amounts of sunshine. 

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Researchers noted that areas such as New England are more at risk than southern regions when evaluating based solely on weather conditions. This will be a concern for people in those states after the humid, sunny and hot summer season has passed.  

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