The World Meteorological Organization (WMO) has not yet certified that this week's temperatures are all-time weather records for Antarctica, though the Argentinian weather service has verified that the temperatures measured at Esperanza Base and Marambio Base were the highest ever measured at each site.
The Antarctic Peninsula is one of the fastest warming spots on Earth. A 2012 Climate Central post by Michael Lemonick on climatecentra.org documented how while the Earth as a whole warmed up by 1.3°F between 1900 and 2011, the Antarctic Peninsula warmed by 5°, forcing massive ice shelves to disintegrate and penguin colonies to collapse.
A 2012 study published in the journal Nature found that the recent warming is faster than 99.7% of any other given 100-year period in the last 2000 years.
Source: wunderground.com