Could the ambient higher temperature decrease the transmissibility of COVID-19 in China?

Wang, Qingan; Zhao, Yu; Zhang, Yajuan; Qiu, Jiangwei; Li, Juan; Yan, Ni; Li, Nan; Zhang, Jiaxing; Tian, Di; Sha, Xiaolan; Jing, Jinyun; Yang, Chan; Wang, Kairong; Xu, Rongbin; Zhang, Yuhong; Yang, Huifang; Zhao, Shi; Zhao, Yi

BACKGROUND: Existing literatures demonstrated that meteorological factors could be of importance in affecting the spread patterns of the respiratory infectious diseases. However, how ambient temperature may influence the transmissibility of COVID-19 remains unclear. OBJECTIVES: We explore the association between ambient temperature and transmissibility of COVID-19 in different regions across China. METHODS: The surveillance data on COVID-19 and meteorological factors were collected from 28 provincial level regions in China, and estimated the instantaneous reproductive number (R(t)). The generalized additive model was used to assess the relationship between mean temperature and R(t). RESULTS: There were 12745 COVID-19 cases collected in the study areas. We report the effect of temperature on R(t) is likely to be negative but not of statistical significance, which holds for most of included regions except for those in North China. CONCLUSIONS: We found little statistical evidence for that the higher temperature may reduce the transmissibility of COVID-19. Since intensive control measures against the COVID-19 epidemics were implemented in China, we acknowledge this may impact the underlying effect size estimation, and thus cautiousness should be taken when interpreting our findings.