When have we fog?
When the air near the earth is slightly cooled, its vapor is condensed into fog.
When have we clouds?
When the air higher above the earth is slightly cooled, its vapor is condensed into clouds.
When have we mist?
When the air is a little more cooled, its vapor is condensed and mist falls.
When have we rain?
When the air is still more cooled, its vapor is condensed and rain falls.
When have we snow?
When the air is cooled below thirty-two degrees, its vapor is condensed and frozen into snow.