Nanning on New Year's Eve

When Nanning was attacked by several cold air, the temperature rose rapidly due to the warm and low pressure in the south, and the air saturation reached over 98%, but the indoor temperature was still low. After warm and humid air enters the room, it is easy to condense into water droplets on cold mirrors, glass and metal guardrails, and gather a lot of water vapor on walls, paper and woolen goods, which is called "returning to the south sky".

This is because the unsaturated warm and humid water vapor in the air mass becomes saturated water vapor when it drops to the dew point temperature, and the saturated water droplets adhere to the building. The lower the temperature of the building, the more obvious the humidity phenomenon is.