Preliminary evidence that higher temperatures are associated with lower incidence of COVID-19, for cases reported globally up to 29th February 2020

Melanie Bannister-Tyrrell; Anne Meyer; Celine Faverjon; Angus Cameron

An open-source line list of confirmed COVID-19 cases was downloaded on March 2 nd 2020 [8] . The line list included data on confirmed cases up to February 29 th 2020 for all countries, including China. Cases were aggregated to the first-level administrative division (ADM1) in which they occurred, as defined by the Global Administrative Areas dataset (https://gadm.org/, accessed March 4 th 2020). This corresponds to the first-level administrative unit within each country, usually described as a state or province. The reported coordinates of the case (variably a point location, city centroid, or different subnational administrative levels) were used to determine the ADM1 in which the case occurred. For each ADM1, an observation period was defined as period from the date of onset of symptoms of the first reported case for that ADM1 to February 29 th 2020. When information regarding onset of symptoms of the first reported case was missing, the confirmation date of the first reported case was used instead.