First of all, northerners may take a bath by the hour, so they can't wait to wipe off all the dust until the washed water is clean. In the south, because the weather in the south is generally humid, and because southerners take a bath almost once or twice a day, southerners don't spend too much time taking a bath, usually only ten to twenty minutes, and it will be particularly hot in the south in summer.
Secondly, southerners will think that bathing is a relatively private behavior, so under normal circumstances, one person has one bathroom, each with its own purposes and does not interfere with each other. Everyone washes for more than ten minutes and washes away all fatigue, even if it is over. In the north, northerners like to take a bath in big bathhouses and wash all the places until their bodies turn red. Therefore, it is unusual for many southerners to take a bath in the north.
Thirdly, because of the cold weather in the north, basically every household has floor heating, so northerners spend more time in the bath, while for the south, winter is very cold, especially in some places where there is no floor heating and air conditioning, so southerners spend less time in the bath.
Many southerners are not used to bathhouses in the north for the first time, and many northerners are particularly uncomfortable when they go to the south, which is also caused by geography and humanities.