But researchers now suggest that humidity, more than heat, may prove effective at choking off the person-to-person transmissions that make the disease’s spread so dangerous.
Still, it’s far from settled science.
Dr. Alan Evangelista, a microbiology and virology professor at St. Christopher’s Hospital for Children in Philadelphia, has studied common coronaviruses and influenza particles for eight years.
He says his research indicates that “the size and overall composition of [the novel coronavirus] particle is similar to other coronaviruses we have tested” -- meaning his findings may shed light on how the coronavirus spreads, and possibly how it dies out.
Those findings show that “transmission is highly efficient under drier and colder conditions,” but far less so in a humid environment.
According to the Centers for Disease Control and Prevention, the novel coronavirus is thought to spread mainly from person-to-person through respiratory droplets when an infected person coughs or sneezes. Those droplets can be inhaled into the lungs or land in the mouths or noses of people nearby. The droplets are also believed to linger on hard surfaces, which other people might later touch.
“As humidity increases, the viral droplet size is larger and settles out of the air rapidly,” Evangelista found, according to a statement he provided to ABC News on his research.
“In contrast, in low humidity, there is rapid evaporation of respiratory droplets,” he continued. “They remain airborne for prolonged periods, increasing the time and distance over which transmission can occur.”
Evangelista argues that while “there are obviously no guarantees that COVID-19 will behave exactly like the known coronaviruses … the laws of physics should apply.”
