When the weather is sultry, the ground will be very wet and even water will come out.

The weather is sultry: the air is hot and there is a lot of steam.

The floor, especially marble, is very cold relative to the air, so the water vapor condenses when it is cold, and it comes out when it is too much.

Or the ground is too wet. For example, once we had a heavy rain, the water seeped below the surface and turned against the water at noon.