evidence: Something strange is happening to the Antarctic’s sea ice. The areal expanse of floating ice fringing the continent is not only at a record low for this time of year — surpassing a record just set in 2022 — but ice extent has been hitting record lows throughout the year. [...] The amount of ocean around Antarctica covered in sea ice in 2023 (red) has stayed well below the average from 1981 to 2010 (black). Sea ice expanse hit a record low in late February — surpassing a record set just in 2022 (blue). The sea ice expanse for every year from 1981 to 2021 is shown in gray. Even as the Southern Hemisphere shifted into winter, Antarctic sea ice remained at record low levels. On June 27, the ice was dotted across about 11.7 million square kilometers of ocean. That’s about 2.6 million square kilometers below the 1981–2010 average, and about 1.2 million square kilometers below the previous lowest extent on record for June 27, set in 2022.