Why does the flu always happen in winter?

Winter is always the high incidence season of influenza, because not only the temperature changes greatly in winter, but also it is dry in winter, and people don't pay much attention to the temperature changes, so influenza is more rampant in this understanding!

The biggest difference between the north and the south is that the winter in the north is too dry, which is easy to cause respiratory infections. Most people cough first when they catch a cold, but it's different in the south. The climate in the south is humid. Although the flu is rampant everywhere in winter, it seems to be more serious in the north.

Take my home as an example. I watched a video with my family the other day and found that they all caught a cold. At the same time, I was very worried and suddenly wondered if I didn't pay attention to keeping warm. As a result, my mother told me that it hardly snowed this winter, and it was particularly dry. Many people catch a cold, especially the temperature difference between indoor and outdoor is very large, which makes them scary when they go out. As a result, the flu spread indefinitely.

It can be said that large temperature difference, dry climate and low temperature are all important causes of influenza.