Covid: does extreme cold curb the spread of the virus?

Published by Anne-christine C. · Photos by My B. · Published on 12 February 2021 at 13h13
Does extreme cold France has been experiencing over the past couple of days curb the spread of Covid-19? As we know cold improves the spread of the virus, things are different when temperatures drop below 0°C. Here is more on the matter.

Snowfalls, cold temperatures, France has been experiencing a cold snap for a few days. Temperatures even dropped to -12°C (10.4°F) in Hauts de France and black ice spreads in the morning. What impact does extreme cold have on coronavirus?

So far, scientists and epidemiologists say cold improves the spread of the virus. Humid air, low temperatures, this is the winning combo for the spread of Covid-19. But what does “low temperatures” mean? According to a study conducted in December 2020 by Predict Services, Météo France and Airbus’s natural risk managing subsidiary, it is when it is between 3 and 17°C (37.4 and 62.6°F) that the virus actively spreads. Yet, when the mercury dips below 0°C (31.9°F), as for the past couple of days, everything changes.

As a matter of fact, the virus transmission conditions depend on two factors: the air humidity rate and the temperature. When the air is humid, droplets carrying the virus tend to go up and spread. When the air is very dry, droplets fall on the floor.

With the very cold weather that has been experienced over the past days, as explained by Alix Roumagnac from Predict Servicesdroplets carrying the virus outside the human body (when one coughs or sneezes) freeze, cannot stay in the air and fall to the ground”. Here is why the cold snap enables a lower spread of the virus. At least, we are not frozen for nothing!

Yet, let us not forget that other cold-related factors influence the spread of the virus and whatever the temperature. The lack of sun and vitamin D makes one’s body more vulnerable, and cold also influences one’s mucous. As explained by epidemiologist and National Academy of Medicine Covid-19 cell president Pr. Yves Buisson, “cold leads to alteration of our respiratory mucous, the slight inflammatory state of our mucous makes it easier for the virus to append itself within the body when one is close, improving infection then”.

And of course, there are one’s behavior in the event of cold, such as overcrowding, gathering and one airs rooms less.

So, to make sure this cold snap can curb the spread of the virus, pay attention to what you do!

Practical information