Weather and human mobility impact COVID-19 cases

Different countries around the world took various measures to contain COVID-19. But weather may also have affected when and where the disease spread. Mendes et al. show the relevance of meteorological data on human mobility and consequently on the new cases of virus infection.

The researchers studied the temporal relation between individuals newly infected by the coronavirus, human mobility, and weather in Sao Paulo, Brazil from February 26 to June 28, 2020.

Within human mobility, they looked at grocery stores and pharmacies, parks, residential, retail and recreational spaces, as well as public transit stations and workplaces. The meteorological variables they studied included radiation, precipitation, temperature, air pressure, and humidity.

During a weekend with heavy precipitation, for instance, people were more likely to stay home instead of going to communal parks and recreational spaces. Human contact was lower and consequently there was a lower probability of new virus infections compared to a sunny weekend where people left their homes to socialize.

Specifically, the researchers found that social behavior most affected the earlier stages of the disease, 8 to 17 days after exposure. Fewer movements in recreation and transit stations, and increasing values of maximal temperature for instance, had a strong correlation with the number of infected individuals 17 days later.

“Scanning the whole period of the data and not only the early stage of the disease, what surprised us the most was the crucial role the Municipal Decree declaring an emergency in the city of São Paulo played in influencing the number of infected individuals,” said author Marcus W. Beims.

Source: “Temporal relation between human mobility, climate and COVID-19 disease” by Carlos F. O. Mendes, Eduardo Luís Brugnago, Marcus W. Beims, and Alice Grimm, Chaos (2023). The article can be accessed at https://doi.org/10.1063/5.0138469 .