According to a preliminary study by Chinese researchers that examined how coronavirus progressed in various countries as the temperature changed, the transmission rate to other people from an infected person was reduced as the temperature climbed.

Ronald Bailey at Reason notes how the numbers in the Chinese study worked:

In cold dry weather the basic reproduction number (R) of the new coronavirus is somewhere between 2 and 3—that is, each infected person passes along the virus to an average of 2 to 3 other people. Once they’ve crunched the data, the researchers find that a one degree Celsius increase in temperature and one percent increase in relative humidity lower the R value by 0.0383 and 0.0224, respectively

The researchers studied Iran, Japan, and Korea, where the weather is generally lower, as well as the humidity, and compared them to Malaysia, Singapore and Thailand, where the average temperatures are warmer with higher average humidity.

Bailey theorizes that in Washington, D.C., where the average high temperature is 56 degrees Fahrenheit and the average humidity is 58% in March, the temperature would rise to 87 degrees Fahrenheit and 71% humidity in August. He writes that R would drop from 2 to 1.047, cutting R nearly in half.

Bailey cautions that even if the summer proves beneficial in dealing with the coronavirus, “The second winter wave of the 1918 Spanish flu was far more deadly than the original outbreak.” But he concludes, “Nevertheless, a dog days lull in the epidemic would provide a breathing spell during which our health care system could substantially beef up treatment and mitigation efforts. It might even allow researchers enough time to discover and deploy effective pharmaceutical therapies for the disease.”

Jeremy Brown, MD, director of the Office of Emergency Care Research at the National Institutes of Health and author of Influenza: The Hundred-Year Hunt to Cure the Deadliest Disease in History, told Health, “COVID-19 will slowly recede as the warmer spring climate provides conditions that the virus cannot tolerate. Spring will be very welcome this year.”

Dr. Alan Evangelista, a microbiology and virology professor at St. Christopher’s Hospital for Children in Philadelphia, told ABC News, “The size and overall composition of [the novel coronavirus] particle is similar to other coronaviruses we have tested,” adding, “As humidity increases, the viral droplet size is larger and settles out of the air rapidly. In contrast, in low humidity, there is rapid evaporation of respiratory droplets. They remain airborne for prolonged periods, increasing the time and distance over which transmission can occur.” He continued that while “there are obviously no guarantees that COVID-19 will behave exactly like the known coronaviruses … the laws of physics should apply.”

National Geographic spoke to David Heymann from the London School of Hygiene and Tropical Medicine, who warned that making predictions about the coronavirus could be dangerous, saying, “The risk of making predictions without an evidence base is that they could, if they prove to be wrong, be taken as verity and give a false security. The emphasis today should continue to be on containment to elimination where possible.”