In the winter months the sea of Antarctica will become sheets of white ice, sometimes 3 metres thick. Nearer the shore, the sea is almost constantly covered in ice and the water below it ranges from minus 0.8 to minus 2 degrees celsius year round. This, however, depends on the location as freshwater freezes at higher temperature than saltwater.
Antarctica's location means that it receives significantly less sunlight than the other continents. The south pole will receive little sunlight and the light which is present, is reflected by the white ice caps. Also, Antarctica is quite bare and does not have many large land masses to store the heat. In addition, the curvature of the Earth means that the sun's rays are 'spread out'. The sun is at a very low angle in the sky (for the polar regions) and can not effectively heat the polar reasons.
Antarctica spends 6 months in complete darkness and the other 6 months in daylight. You could say that it is similar to only having a two day year.