Transmission of COVID-19 was slower but more sustained in warm climate

Abstract Background The COVID-19 novel virus has caused huge damage to public health around the world. Revealing the influencing factors affecting the transmission rate of COVID-19 is essential to take effective control measures. However, the association between transmission of COVID-19 and climate factors remains elusive with high uncertainty. Methods By using an extensive global dataset covering 617 time series from China, USA, Europe, and the rest of the world during 1/1–31/12 2020, we estimated the transmission parameters of COVID-19 and modeled the effects of the human and climate factors on COVID-19 transmission. Results We demonstrate that the transmission rate of COVID-19 was lower in warm climate in China, Europe, USA and the world, and in wet climate in China and Europe after excluding the confounding factors. The maximum transmission rate of COVID-19 seemed to have a peak temperature around 11.2°C in China and the world. The control efficiency (i.e. decreasing speed of transmission rate) in China, USA and the world was lower in warm and wet condition. Conclusions Our study suggested that in summer seasons, the transmission risk of COVID-19 would increase in the high-latitude or high-altitude regions but decrease in low-latitude or low-altitude regions. The area with the 7.8°C isocline between October and January which overlap with the major epicenters of COVID-19 should be investigated as a priority in searching for the natural hosts of COVID-19 and their habitats and movement.