Higher solar irradiance is associated with a lower incidence of COVID-19

Clin Infect Dis. 2020 May 19;ciaa575. doi: 10.1093/cid/ciaa575. Online ahead of print.


We studied the relationship between the incidence of coronavirus disease 2019 (COVID-19), demographical, and climatological measurements in different regions across the world. Lower solar irradiance and higher population density were independent predictors of greater COVID-19 outbreaks. Further studies on the potential protective effect of sunlight over COVID-19 are warranted.

Keywords: COVID-19; SARS-CoV-2; climatological factors; incidence; solar irradiance.