Abstract
While strong non-medical interventions such as stay-at-home strategy were implemented in the reaction to the novel coronavirus pandemic (COVID-19), it is essential to examine the extent to which these interventions were effective enought in controlling the infections in order to ensure that the future countermeasures against pandemic will be appropriate. In this study, we analyzed the statistical relationship between the spread of the novel coronavirus (SARS-CoV-2) in Japan and the reduction rate of going-out and seasonal factors that may have contributed to the outbreak. The results showed that the spread of SARS-CoV-2 (weekly number of positive cases) has a strong positive correlation with the seasonal epidemic pattern of conventional coronaviruses and a strong negative correlation with the weekly average temperature. However, on the other hand, it was not significantly correlated with the weekly average reduction rate of going-out. Furthermore, a multiple regression analysis suggested that average temperature has the dominant effect on the spread of SARS-CoV-2.
