Scientists have measured what is likely the highest temperature ever on Antarctica: 63.5 degrees Fahrenheit (17.5 Celsius).
The measurements were made last Tuesday at Argentina's Esperanza Base, on the northern tip of the Antarctic Peninsula, according to the meteorological website Weather Underground. The previous hottest known temperature on the continent was 62.8°F (17.1°C), recorded at Esperanza Base on April 24, 1961.
The Weather Underground called last week's temperatures a "remarkable heat wave," although they occurred during the end of the austral summer, when Antarctic temperatures are typically highest.
The temperature has yet to be certified as an official record for the continent by the World Meteorological Organization.
It's hard to draw much conclusion from a single temperature record, cautions Gavin Schmidt, a climate scientist with NASA's Goddard Institute for Space Studies in New York City. Last year Antarctica also logged a record cold temperature, he notes.
What's more important are the long-term trends, says Schmidt. And when it comes to Antarctica, he points out, the past few years "have actually been quite complex."
The world's ocean has been warming rapidly, absorbing much of the planet's excess heat. As a result, large glaciers on or around Antarctica that come in contact with the warming water have been melting rapidly. But some other glaciers farther inland on the continent are actually growing.
"That has not been satisfactorily explained," says Schmidt.
The science is particularly complex because the ozone hole continues to affect the region's climate in ways that aren't well understood. And global circulation of winds and currents remains a challenge for scientists to grasp.
"One record warm temperature doesn't cut through all that complexity," says Schmidt. (Learn about the recent cold snap in the U.S.)
When it comes to the whole planet, the Earth remains on track to warm by an average of at least two degrees C (3.6 degrees F) by the end of the century, scientists report, although precisely how much is expected to depend on countries' abilities to reduce emissions of heat-trapping greenhouse gases.