Paul Dabisch, a senior research scientist at the Department of Homeland Security’s biodefense research laboratory, said that initial lab tests show sunlight, higher temperatures and humidity are hurdles for the survival of the coronavirus.

“What we have found so far is that sunlight seems to be very detrimental to the virus,” Dabisch explained. “And so within minutes, the majority of the virus is inactivated on surfaces and in the air in direct sunlight.”

Research done at the National Biodefense Analysis and Countermeasures Center was first revealed by William Bryan, the acting undersecretary for science and technology at Homeland Security. He described the “most striking observation to date,” that ultraviolet rays from the sun may have a powerful effect on the virus.

During a White House briefing April 23, Bryan reported, “The virus is dying at a much more rapid pace, just from exposure to higher temperatures and just from exposure to humidity.”

An analysis in Swiss Medical Weekly found that “seasonal variation in transmissibility has the potential to modulate” the spread of the coronavirus.

“I think it is highly likely that it will show winter peaks in temperate areas of the world,” co-author Jan Albert of Sweden’s Karolinska University Hospital said by email.

But even with that finding comes caution: “The onset of spring and summer could, for example, give the impression that (the coronavirus) has been successfully contained, only for infections to increase again in 2020-2021 winter season,” the Swiss Medical Weekly paper said in March.

Other studies have drawn correlations between cooler climes and higher transmission rates, but socioeconomic factors can also be at play, including the quality of health care, underlying health conditions and social distancing protocols in a particular region, Relman said.

Although the coronavirus may not survive as well on laboratory surfaces in warmer, more humid weather, it might still be easily transmitted from person to person, the experts said.

Albert said the coronavirus “will become endemic” like the four strains associated with the common cold.

“Given the magnitude of the global spread, it is hard to see that it will be contained and disappear,” he said. “It is likely that it will become a fifth endemic coronavirus.”

Dr. Arnold S. Monto, an epidemiology professor at the University of Michigan’s School of Public Health, argued there’s little evidence so far that this coronavirus will act like its endemic relatives and take a summer break.

“This pandemic virus is behaving differently,” he said by email. “The common viruses rarely cause severe disease, so we are not sure if they will behave similarly.”

As such, people should not expect to relax their precautions much in warmer months.

“It is important that individuals still do what they can to protect themselves and others, including wearing masks, washing their hands and maintaining appropriate physical distances,” said Bednarczyk of Emory University in Atlanta.

Stanford’s Relman said: “It may turn out the summer is a better time, but we don’t want to wait and hope and find out we’re wrong. It’s much more wise to say, ‘Let’s not count on it.