Effect of Ambient Temperature on COVID-19 Infection Rate

Abstract

COVID-19 has been declared a pandemic by WHO, and is rapidly spreading throughout the world. Scientists hypothesize that the disease is less infective as temperature rises due to related diseases like the common flu exhibiting such behavior. This white paper analyses provincial confirmed coronavirus cases in China from the 22nd of January to the 16th of February. Taking 5-day time lag of average temperature and dropping provinces with an average temperature below 5 degrees; we find that temperature is a significant explanatory variable for why cases spread faster on certain days than others. On average each additional centigrade above 5 degrees is associated with 1.2 percentage point decrease in the percentage increase in confirmed cases. Considering the average percentage increase in the sample is 12% per day, this means that an increase of an increase of 1 degree Centigrade is associated with a 10% reduction in infectiousness above 5 degree centigrade if the country in question has successful mass quarantine and social distancing methods in place. Contrary to prior evidence, we find conflicting evidence that humidity is related to infectiousness of COVID-19 with the most likely scenario being that it does not have an effect on infectiousness. These preliminary results suggest that temperature has a massive effect on how rapidly the Coronavirus spreads during certain conditions. We recommend that that southern hemisphere countries prepare for increasing caseload, and northern hemisphere countries limit air conditioning.