At midday in winter in which direction is the sun?

It depends on what day of the year it is. In the Northern hemisphere, North of the Tropic of Cancer, at noon local mean time the Sun will be as North as it can be, but it will be South of you. Conversely, in the Southern Hemisphere, South of the Tropic of Capricorn, at noon local mean time the Sun will be as South as it can be, but it will be North of you. In between the two tropics, again it will depend on the time of year, and where you are, but the Sun could be directly overhead, or North of you, or South of you.

This is all because the Earth's axis is tilted 23.5 degrees with respect to the plane of its orbit around the Sun.