On Europe 1, Alix Roumagnac, CEO of Predict Services, returned on Friday evening to the ongoing research on the link between weather conditions and transmission of Covid-19.

According to him, temperatures around 6-7 degrees are particularly conducive to contamination, as the droplets remain suspended in the air longer.

ANALYSIS

More than a year after the start of the health crisis, the Covid-19 has not finished revealing all its secrets, and researchers continue to work to try to better understand the various factors allowing the rebounds of the epidemic circulation .

Among the factors studied: the weather.

Guest on Friday from Europe 1, Alix Roumagnac, CEO of the Predict Services hydrometeorological monitoring site, summarized the current state of knowledge on the subject.

"It's a complex pandemic. The weather is one of the parameters to be integrated and analyzed," he recalls in particular. 

>> LIVE - 

Coronavirus: follow the evolution of the situation Friday February 26

"The droplets are dependent on the hygrometric conditions"

In March, "studies were identified which showed that temperature and humidity could influence the transmission of the virus," he explains.

"One of the factors is that the virus is carried by the small droplets, the aerosols."

However, adds Alix Roumagnac, "these droplets are dependent on hygrometric conditions".

For example, "when it's very cold like early February in the North, at -8, -10 degrees, they will fall to the ground very quickly".

And when it's hot like this summer, with more than 15-20 degrees, "they evaporate when it's dry, where they will agglomerate and fall to the ground when it's wet". 

What are the temperatures that best promote transmission?

"There is an area which seems more favorable around 6-7 degrees, where these droplets seem to stay the most in suspension," replied the guest from Europe 1. And these temperatures have been observed in recent weeks.

"Perhaps that's why we felt an increase in the curves," said Alix Roumagnac. 

The influence of storm Alex

Conversely, last summer, with its warm temperatures, was marked by a decline in the epidemic, before a recovery in the fall.

"The storm Alex brought down cold air from Iceland and put France in the most favorable conditions, particularly the Massif Central and the north of the Alps. And a few days later we had the restart of this second wave ", explains the specialist. 

CORONAVIRUS ESSENTIALS

> Are private parties really prohibited with the curfew?

> Coronavirus: a universal vaccine available "towards the end of the year"

> The English variant would cause slightly different symptoms

> Audio, webcams ... When technology adapts to teleworking

> Containment is good for the planet

On Europe 1, Alix Roumagnac recalls that the weather is only one factor among others and that barrier gestures and measures such as curfews are essential.

"The effect of the measures is very important. The second decade of January was very conducive to transmission (…) and I think that if we had not had these measures, we would have had a third wave."