UV light is known to kill viruses and bacteria in an effective way. High temperatures (56 deg. C) were found to kill COVID-19 virus. Temperature is linked to the efficiency of the immune system. Cilia cells of the immune system work better under warm temperatures. These statements have been documented in the literature. Why then these relationships are not mentioned by public authorities ?
Maybe I will answer my own question.
Big Pharma might not be interested in people finding links between viruses/bacteria and weather. You can move to more favorable places to reduce the risk (under sunshine with a lot of UV and higher temperature) and not need Big Pharma's medicine.
Another possibility is lack of multi-disciplinarity among researchers which think that weather is not related to viruses.