Why is the weather so bad recently?

The main reason is that the southwest warm and humid airflow from the Bay of Bengal is very strong this year. This powerful southwest warm and humid airflow from the Bay of Bengal carries a lot of water vapor. After entering the territory of our country, it pushed forward vigorously along the northeast direction, swept across most parts of our country, and reached the Yangtze River estuary smoothly and unimpeded. At the same time, the strong cold air from the northern Urals Mountains in Siberia has successfully arrived in northern South China and southern Jiangnan. Once there is enough water vapor and clear cold air, the local weather is easy to be a snowstorm.