Will Spring Temperatures Stop Coronavirus?

Like everyone else, I am watching the Coronavirus. It has become a world-wide threat and governments are scrambling for a response. The Chinese Center for Disease Control and Prevention released a summary of its cases this week. Some of the jarring fatality rate numbers summarized in a JAMA Network article include:

• 2.3% Overall
• 14.8% age >= 80
• 8.0% age 70-79
• 49.0% in critical cases

There are all types of conspiracy theories, bad science and misinformation spreading as rampantly as the virus itself. As an atmospheric sciences professor and meteorologist, a question that I am increasingly receiving is “Will warmer Spring temperatures help stop the Coronavirus?” Herein, I provide what we know at this point about the answer to that question.

Before I delve into that question, I offer a disclaimer: My doctorate and other degrees are in physical meteorology from Florida State University. I do not claim to be an expert in public health or infectious diseases. Unlike many people in this “Dunning-Kruger Effect”-laced society, I do not believe my knowledge or Tweet on every subject matter is superior to the experts. For example, I saw a Facebook post on a friend’s page that said, “Just because the Centers for Disease Control (CDC) says it, doesn’t mean it is true.” After I collected my eyes from the back of my head, I wondered why she believed her declaration that information from CDC is fake would be credible. However, I digress. Let’s get back to the topic at hand.

The CDC has provided an excellent “Frequently Asked Questions (FAQ)” website on Coronavirus, which is officially designated as COVID-19 by the World Health Organization (WHO). According to the CDC, “There are many types of human coronaviruses including some that commonly cause mild upper-respiratory tract illnesses.” However, COVID-19 is novel and has not be previously detected in humans. With that backdrop, let’s answer the question about whether warmer weather will help stop the spread of COVID-19.

Candidly, the real answer is probably not going to be that comforting. We don’t know. According to the CDC FAQ page, “It is not yet known whether weather and temperature impact the spread of COVID-19.” There is probably some assumption that this will be the case because many other viruses, including the common cold, bird flu or influenza, are more actively spread during the colder months.

but that does not mean it is impossible to become sick with these viruses during other months. At this time, it is not known whether the spread of COVID-19 will decrease when weather becomes warmer. There is much more to learn about the transmissibility, severity, and other features associated with COVID-19 and investigations are ongoing.

In places like the U.S. and China, colder seasons are associated with flu-like virus but in the humid tropics, studies have shown that flu can thrive at any time of the year. William Schaffner, a professor of infectious diseases at Vanderbilt University, told Marlene Cimons of NexusMedia that it is not clear why flu viruses thrive year round in the tropics. Cimons, in a 2019 article, pointed out that infectious disease scientists fear as warmer, more humid conditions inch poleward, flu-like viruses may start to thrive longer as they do in the tropics. A 2020 study published in Environmental Research Letters found that extreme and rapid variability in weather conditions were associated with increased influenza epidemic risk at latitudes beyond the tropics. They concluded that rapid weather variability in Autumn is a possible predictor of influenza epidemic the following months and a warming climate, as studies have shown, will continue to alter such variability.

At this time, the CDC confirms that there is no clear consensus on how the warm season will impact COVID-19. Additionally, I want to clearly state that my aforementioned references to climate change – virus literature is not an attempt to tie COVID-19 to climate change. Sadly, I have to write things like that because people with extreme positions on either side of the ledger will misuse what was intended as contextual science.