No, the Bellingshausen Sea Did Not See Temperatures 20°C Above Average — Here's What Actually Happened
“Temperatures in the Bellingshausen Sea region peaked at 15.4°C, representing a departure of more than 20°C above historical averages”
The argument in brief
A viral claim states that the Bellingshausen Sea hit 15.4°C with a departure of more than 20°C above historical averages. This is partially false. While the region has experienced real and serious warming, every major dataset — including NOAA, ECMWF ERA5, and the University of Maine's Climate Reanalyzer — puts Bellingshausen Sea anomalies in the 3–10°C range during extreme events, not 20°C-plus. The dramatic figures appear to have been borrowed from a completely different location: Antarctica's interior.
Why it spread
The March 2022 Antarctic heat event was genuinely shocking, and legitimate news coverage produced some staggering numbers. As those stories spread on social media, figures from the remote interior — where the most extreme anomalies occurred — got mixed up with conditions in the Bellingshausen Sea. Extreme statistics travel fast online, especially when they confirm what people already fear or want to argue about climate change.
A striking set of temperature figures has circulated online, claiming the Bellingshausen Sea — a stretch of ocean off West Antarctica — reached 15.4°C with temperatures more than 20°C above normal. The verdict: partially false. The warming in this region is real and alarming, but the specific numbers cited are not supported by any peer-reviewed source or major climate dataset.
The confusion almost certainly traces back to the extraordinary Antarctic heat event of March 2022. That event was genuinely historic — but the mind-bending anomalies, some near 40°C above normal, occurred deep in the continental interior at stations like Concordia on the East Antarctic plateau, as reported by the Washington Post and confirmed by ECMWF ERA5 reanalysis data. The Bellingshausen Sea is a maritime region with a completely different climate baseline, and oceans simply don't swing that far.
Every credible source tells the same story for the Bellingshausen Sea specifically. NOAA's surface temperature analysis, the ECMWF ERA5 dataset, and the University of Maine's Climate Reanalyzer all document anomalies in the 3–10°C range for this region during extreme events — significant, but nowhere near 20°C-plus. A Nature Communications study on the 2022–2023 Antarctic sea ice collapse, which highlighted the Bellingshausen Sea as one of the hardest-hit areas, similarly documented surface air temperature anomalies of 5–10°C. The World Meteorological Organization has no verified record of a 15.4°C reading or a 20°C departure for this maritime zone.
To be clear: none of this means the situation in the Bellingshausen Sea is fine. It is not. The region has contributed to record-shattering sea ice loss, and anomalies of 5–10°C in a maritime environment are genuinely serious. Understating the real problem is just as unhelpful as overstating it.
This kind of error spreads because real, alarming events generate real, alarming numbers — and once those numbers are in circulation, they get detached from their original context. A figure that accurately describes one location gets applied to another. Watch for claims that cite a single dramatic statistic without specifying exactly where and when it was measured. Antarctica is a continent the size of the US and Mexico combined; conditions vary enormously across it.
Sources
- Nature Communications - Antarctic Sea Ice Anomaly 2023
The 2022-2023 Antarctic sea ice extent reached record lows, with the Bellingshausen Sea among the most affected regions, but temperature anomalies documented in peer-reviewed literature were in the range of 5-10°C above average for surface air temperatures, not 20°C.
- NOAA Global Surface Temperature Analysis
NOAA records for Antarctic regional surface temperatures show anomalies in the Bellingshausen Sea area during the 2022 heat event were significant but well below the 20°C departure figure cited in the claim.
- Washington Post - Antarctic Heat Wave March 2022
The March 2022 Antarctic heat event saw temperatures approximately 40°C above normal at the interior of the continent (Concordia station), but coastal Bellingshausen Sea region anomalies were far more modest, and absolute temperatures of 15.4°C were not documented for this maritime region.
- European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 Reanalysis
ERA5 reanalysis data confirmed extraordinary Antarctic temperature anomalies in March 2022, primarily over the East Antarctic plateau. The Bellingshausen Sea (West Antarctica) showed elevated anomalies but the specific figures of 15.4°C absolute temperature and 20°C+ departure are not corroborated by this dataset.
- World Meteorological Organization - Antarctic Climate
WMO documentation of Antarctic temperature records does not include a verified 15.4°C reading or 20°C+ anomaly for the Bellingshausen Sea specifically; the most extreme anomalies recorded were inland, not in this maritime region.
- Climate Reanalyzer - University of Maine
The University of Maine's Climate Reanalyzer, which tracks Antarctic temperature anomalies in near-real-time, shows the Bellingshausen Sea region experiencing anomalies typically in the 3-8°C range during extreme events, with no verified instance of a 20°C+ departure for this specific maritime area.