This is something I've observed when boiling water for tea.
I place the water in a metal pot and bring it almost to a boil. The water level is at about the middle of the height of the pot.
When the water is ready, I pour the water in the cup. Suddenly, when coming into contact with the side of the pot (that was not in contact with water beforehand), the water starts violently boiling and spraying around.
Clearly this suggests that the upper side of the pot is much hotter than the water itself. But why? After all, the water is in the pot, and the upper side of the pot is farther from the heat source than the water.
Why does this happen?