Dr Siddarth Sridhar from HKUMed's Department of Microbiology discusses the relationship between temperature, UV radiation, and the spread of COVID-19. He explains that while warmer temperatures and higher humidity may not be favorable for coronavirus survival in a laboratory setting, other factors such as public health interventions, border controls, and social distancing measures can affect the transmission of the virus in different cities. Additionally, people tend to stay indoors in climate-controlled environments, where the virus can still transmit easily.