emperatures on Seymour Island off the coast of the Antarctic Peninsula peaked at 20.75 °C (69.3 °F) on February 9, The Guardian reports. Days earlier, the nearby Argentinian Esperanza Base recorded a record-setting 18.3 °C (64.94 °F), according to the World Meteorological Organization. The previous record of 17.5 °C (63.5 °F) occurred in 2015.
The World Meteorological Organization (WMO), an agency governed by the United Nations, keeps the official records. In order to ensure accuracy, there are strict standards regarding calibration, height, and length of service for weather stations. Weather stations are supposed to be two meters tall, while the 12-year-old station at Seymour Island sits half a meter lower. Because temperatures are higher closer to the ground, this discrepancy could prevent the reading from becoming an officially accepted WMO record.
“It is an important measurement, but it will not be recognized by WMO, because it was not measured in [a] standard weather station with a long time record,” Jefferson Simões, a glaciologist at the Federal University of Rio Grande do Sul in Brazil, tells The Washington Post.
WMO’s Weather and Climate Extremes rapporteur, Randall Cerveny, explains in a statement that these short-term temperature boosts are likely due to what’s known as a foehn event. When air hits the face of a mountain, the humidity condenses and turns into precipitation. This process speeds up the air, so what comes down the other side of the mountain is warmer and drier.
The Antarctic Peninsula, located about 500 miles south the coast of South America, has warmed an average of nearly 3 °C over the last 50 years, according to WMO, making it the fastest-warming region on the planet.
“[This record] doesn’t come as any surprise,” Eric Steig, a glaciologist at the University of Washington, tells the Post. “Although there is decade-to-decade variability, the underlying trend across most of the continent is warming."
As Antarctica is currently experiencing its summer months, Steig predicts there will be more record-setting highs in the near future.