Abstract
In this study, we objectively focus on the relationship between the number of coronavirus (COVID-19) cases and key climate variables. We found that the risk of COVID-19 was approximately doubled during warm summer months when the aerosol molecules are likely stimulated by temperature and rainfall. Given that India is currently emerging as the new epicenter for the third and fourth outbreaks of COVID-19, we selected four key hotspot states-Maharashtra, Andhra Pradesh, Kerala, and Tamil Nadu - to closely look into the impact of climate variables on the spread of COVID-19 infected cases during 2020 and 2021. We found that COVID-19 is most active in temperature between 27°C and 32°C, while it is active in monthly average rainfall between 250 mm and 350 mm. This study further confirms that, although temperature and rainfall are not the initial triggers of COVID-19, both variables seem to play significant roles in spreading COVID-19 in India, especially during the summer season of 2020 and 2021, when the Indian summer monsoon was stronger in these four states.