Antarctica is the coldest continent on earth, and has a climate of extremes. The continent is snow- and ice-covered, with freezing temperatures all year round. So-called "Catabian winds" can cause violent snowstorms that can last for days, and sometimes even weeks, making it very dangerous to stay outside. Antarctica knows periods of continual daylight an darkness, called "polar summer" (end May - Sept) and "polar winter" (end Nov - March).
The polar summer with daytime temperatures between -20°C and -5°C is the only time to travel to Antarctica, because the conditions are too bad during the winter months, with extreme cold temperatures, violent storms, continous darkness and ice-bound seas.
Note: Be prepared to extreme weather conditions at any time. The Weather can change very quickly in Antarctica, sunshine can change to a serious snowstorm from one moment to another.