The virus that causes Covid-19 spreads fastest at 8.72°C, a new study found after looking at a two-week period of its contagion effect in tandem with the various temperatures in different countries.
But experts are cautioning against thinking the spread will slow down in response to warmer weather, the same way other pathogens that cause the common cold or influenza do.
New study
A team from Sun Yat-sen University in Guangzhou, the capital of south China’s Guangdong province, carried out the study to determine how the spread of the new coronavirus might be affected by changes in season and temperature.
It was published in February but has not been peer-reviewed.
The report suggested heat indeed changes how the virus behaves: “Temperature could significantly change Covid-19 transmission.”
“And there might be a best temperature for viral transmission.”
The analysis found that case numbers went up in tandem with average temperatures up to a peak of 8.72°C and then declined.
As a result, it suggested that “countries and regions with a lower temperature adopt the strictest control measures”.
This was so as the “virus is highly sensitive to high temperature”.
Singapore still has new cases despite warm weather
But this does not mean the virus cannot spread in warm tropical countries such as Singapore.
Singapore has so far seen its fair share of Covid-19 cases, with 150 cases as of March 8.
The Guangzhou team based their study on every novel coronavirus case confirmed around the world between Jan. 20 and Feb. 4.
It took into account more than 400 Chinese cities and regions that were affected during that time.
These were then modelled against official meteorological data for January from across China and the capital cities of each country affected.
“Temperature... could play a significant role in public health in terms of epidemic development and control,” the study said.
It said also that climate may have played a part in why the virus broke out in Wuhan, China where it was first detected.
Warm weather not foolproof solution
Warm weather not being a foolproof solution to curb the spread of the virus was also affirmed in a separate study published in February by a group of researchers from Harvard’s T.H. Chan School of Public Health, but has not been reviewed.
It found that the sustained transmission of the coronavirus and the rapid growth in infections was possible in a range of humidity conditions.
It said an "increase of temperature and humidity as the spring and summer months arrive in the Northern Hemisphere, will not necessarily lead to declines in case counts without the implementation of extensive public health interventions”.
Many national governments and health authorities have said the coronavirus could lose some of its potency as the weather warms up.