A city’s weather could be linked to how hard it got hit by the coronavirus.
According to a study published Tuesday, the amount of time coronavirus-laden droplets last on surfaces depends on the surrounding temperature and humidity, as well as type of surface they settle on.
The virus typically spreads via droplets when an infected person coughs, sneezes, or talks loudly. Because some of those microscopic droplets settle on surfaces, a team of researchers decided to measure how long it took the droplets to dry out, thereby killing the virus inside. The longer that process takes, the more likely it is that the droplets could infect someone new.
The scientists found that higher temperatures and lower humidity dry out droplets faster — which could in part explain why the coronavirus took hold in some geographic areas more than others.
The researchers compared droplets’ average drying time in six cities with differing temperatures and humidity levels. Their results showed that “a longer drying time correlated with a larger growth rate of the pandemic,” according to Raneesh Bhardwaj, one of the study co-authors.
“Certain outdoor weather is something that matters in the growth of infections,” he told Business Insider.