What is the reason why the bathroom smells when it rains?

Because the rainwater fills the underground well, the air overflows, and when it rains, the air pressure is low, which will cause the smell to be unpleasant, causing the bathroom to have a peculiar smell.

First, use an anti-odor floor drain Second, close the edge of the hose at the sink and drain for hand washing, and use a reverse bend for the hose Third, install a reverse air plug at the exhaust port of the bathroom.

Because the air pressure is low on rainy days, the smell of the sewer pipe is emitted upward, so there is a smell. You need to check if there is water in the trap and whether the connection between the trap and the sewer pipe is tight.

The main reason is that the floor drain port, the toilet has no water trap, or the floor drain mouth is not tightly closed.

Sewer problems, let the property people to fix it!