Mount Auburn Hospital Study Suggests Warmer Weather Could Cause ‘Modest’ Decline in Coronavirus

June 04, 2020

New Study Yields Warmer Temperatures Decrease Spread of COVID-19

A new study led by researchers at Mount Auburn Hospital suggests warmer temperatures may decrease the spread of the coronavirus, but it warns that the effect is modest and appears to wane after the temperature rises above 52 degrees. It also cautions that society shouldn’t let its guard down.

“There is an association between temperature and rate of transmission of SARS-CoV-2 virus which may result in modest decline in the community transmission of SARS-CoV-2 with warmer weather. This effect is modest, however, and is unlikely to slow down disease spread if containment measures are relaxed,” according to the study, which was published in the journal Clinical Infectious Diseases.

Dr. Shiv T. Sehra, director of the Internal Medicine Residency Program at Mount Auburn Hospital and first author of the study, also cautioned in a statement Monday that the disease “may get worse in the fall and winter months.”

The study noted that its findings should raise a warning flag for countries in the Southern Hemisphere that are now heading into their winters. And it suggested warmer areas of the United States may have already seen all the coronavirus suppression they’re going to see from warmer weather, after reaching daily maximums of 52.

The study is consistent with other recent research that has suggested that warmer weather could slow down the virus but not stop it. Why some viruses have seasonal cycles is not fully understood.

The Mount Auburn Hospital paper looked at weather data from around the United States and matched it up with reports of new coronavirus cases days later. It examined the period from Jan. 22 to April 3.

Dr. Michael Mina, an epidemiology professor at the Harvard T.H. Chan School of Public Health, said in a news briefing this week that “the temperature issue has come up again and again, again, and I think we still don’t fully understand that part of the biology very well."

But he said, "We’re hoping that that seasonality will remain strong this summer and we’ll see less and less transmission as we move into the summer, all other things held still. We hope that that will play a role.”

He noted there was potential for trouble if society lets its guard down as cooler weather arrives in the fall.

“The backfire that I was going to mention is more long-term, which is if people get very used to having very low numbers of cases throughout the summer, then we might see society get caught a little off guard as the fall comes in and cases really start to sort of rear their head again as a result of changing climate or changing temperatures,” he said.

“We will have to all be really watching as we move into the fall to make sure that we are not inadvertently sort of starting massive outbreaks again once that sort of grace period ends from the summer,” he said.

Researchers from Northeastern University and the University of Pennsylvania Perelman School of Medicine were also involved in the study.

About Mount Auburn Hospital

Mount Auburn Hospital was founded in 1886. A teaching hospital of Harvard Medical School, its mission is to provide clinically excellent care with compassion and to teach students of medicine and the health professions.

Mount Auburn Hospital is a part of Beth Israel Lahey Health, a healthcare system that brings together academic medical centers and teaching hospitals, community and specialty hospitals, more than 4,700 physicians and 39,000 employees in a shared mission to expand access to great care and advance the science and practice of medicine through groundbreaking research and education.

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Kristina Murray

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