Why?

What is most peculiar about this virus is its spreading pattern. The first and most striking experience was right at the beginning, in March 2020. The ski resorts in Italy, Austria and Switzerland as epicenters of the epidemic. How is that at all possible that people get infected while being on a ski holiday?  There have been blames on parties, bars, restaurants... No. This is not at all typical for the flu, skiers do not normally get ill. Also, these parties and bars are not at every ski resort and families with children going to ski resorts generally do not go to parties. Something weird is going on here.

The virus spread was not that intensive elsewhere. Fears of massive virus spreading in the crowded refugee camps in Greece have proved to be unfounded as well as worries about getting infected in shops or on the public transport. Cashiers, receptionists, pharmacy assistants were not typically infected. Not because of masks, antiseptics or barriers - none of these were used at the beginning of the pandemic. 

Based on these and on the fact that the route of infection is through the air I came to the conclusion that some air quality - weather condition may play a very important role here.

First I thought it must be the relative humidity and possibly also low temperature, as it is in the mountains where ski resorts are situated. But later some other facts came into the picture. Mass spreading in meat factories, churches and in mines. Wuhan, Spain, Italy, Izrael, Brazil and the USA. So the high humidity argument no longer seemed to explain all of these. However, there seems to be a more plausible argument: most of these examples of massive spreading are somehow related to condensation, either as a global weather condition of high relative humidity, or as part of a technical process as in case of intensive air conditioning.

How condensation may have a big impact on virus spread? I don't know. But here are my thoughts.