Temperature, Humidity, and Latitude Analysis to Estimate Potential Spread and Seasonality of Coronavirus Disease 2019 (COVID-19)

This cohort study examines the association between climate and the spread of coronavirus disease 2019 (COVID-19) infection. Importance Coronavirus disease 2019 (COVID-19) infection has resulted in a global crisis. Investigating the potential association of climate and seasonality with the spread of this infection could aid in preventive and surveillance strategies. Objective To examine the association of climate with the spread of COVID-19 infection. Design, Setting, and Participants This cohort study examined climate data from 50 cities worldwide with and without substantial community spread of COVID-19. Eight cities with substantial spread of COVID-19 (Wuhan, China; Tokyo, Japan; Daegu, South Korea; Qom, Iran; Milan, Italy; Paris, France; Seattle, US; and Madrid, Spain) were compared with 42 cities that have not been affected or did not have substantial community spread. Data were collected from January to March 10, 2020. Main Outcomes and Measures Substantial community transmission was defined as at least 10 reported deaths in a country as of March 10, 2020. Climate data (latitude, mean 2-m temperature, mean specific humidity, and mean relative humidity) were obtained from ERA-5 reanalysis. Results The 8 cities with substantial community spread as of March 10, 2020, were located on a narrow band, roughly on the 30 degrees N to 50 degrees N corridor. They had consistently similar weather patterns, consisting of mean temperatures of between 5 and 11 degrees C, combined with low specific humidity (3-6 g/kg) and low absolute humidity (4-7 g/m(3)). There was a lack of substantial community establishment in expected locations based on proximity. For example, while Wuhan, China (30.8 degrees N) had 3136 deaths and 80 & x202f;757 cases, Moscow, Russia (56.0 degrees N), had 0 deaths and 10 cases and Hanoi, Vietnam (21.2 degrees N), had 0 deaths and 31 cases. Conclusions and Relevance In this study, the distribution of substantial community outbreaks of COVID-19 along restricted latitude, temperature, and humidity measurements was consistent with the behavior of a seasonal respiratory virus. Using weather modeling, it may be possible to estimate the regions most likely to be at a higher risk of substantial community spread of COVID-19 in the upcoming weeks, allowing for concentration of public health efforts on surveillance and containment. Question Is severe acute respiratory syndrome coronavirus 2 associated with seasonality, and can its spread be estimated? Findings In this cohort study of 50 cities with and without coronavirus disease 2019 (COVID-19), areas with substantial community transmission of COVID-19 had distribution roughly along the 30 degrees N to 50 degrees N latitude corridor with consistently similar weather patterns, consisting of mean temperatures of 5 to 11 degrees C combined with low specific and absolute humidity. Meaning In this study, the distribution of substantial community outbreaks of COVID-19 along restricted latitude, temperature, and humidity measurements were consistent with the behavior of a seasonal respiratory virus; with modeling, it may be possible to estimate areas at high risk of substantial community transmission of COVID-19.