Returning to the southern sky is a phenomenon of warmer weather, mainly because after the cold air leaves, the warm and humid airflow quickly counterattacks, resulting in an increase in temperature and air humidity. Some cold objects are easy to produce water droplets when they encounter warm and humid airflow.
The tropic of cancer in the south is more serious, which is related to the sea and humid air in the south. When Return to the South Sky appeared, the air humidity was close to saturation, and the walls and even the ground would "bubble". Everywhere is wet, and the air seems to be able to wring water out.
When the phenomenon of "returning to the south sky" occurs, the weather is changeable, foggy, sometimes cold and sometimes hot, with low wind speed, much dust and high humidity, which is particularly easy to breed bacteria.
Extended data:
preventive
Close the window sooner or later.
When the damp "returning to the south sky" strikes, everyone must remember to close the windows at home, especially those facing south and southeast, so as not to give any chance for the moisture eyeing outside the window to sneak in.
The most important period of moistureproof is in the morning and evening of every day. The air humidity in these two periods is higher than that at noon. If the doors and windows are not closed in time, water vapor will seriously penetrate into every corner of the house.
In addition, if you think that the indoor air cannot circulate because the doors and windows are closed, I suggest you open the window for a short time at noon.