Before revision:  Using the daily R values from January 21 to 23, 2020 as proxies of non-intervened transmission intensity, we find, under a linear regression framework for 100 Chinese cities , high temperature and high relative humidity significantly reduce the transmission of COVID-19, respectively , even after controlling for population density and GDP per capita of cities.
After revision:  Using the daily R values from January 21 to 23, 2020 as proxies of non-intervened transmission intensity, we find, under a linear regression framework , high temperature and high relative humidity significantly reduce the transmission of COVID-19, respectively , even after controlling for population density and GDP per capita of cities.