Global ocean temperatures hit a record high for June 21, breaking the previous two years' marks—and the pattern matters more than the number.

On June 21, sea surface temperatures outside the polar regions exceeded the highs recorded on the same date in both 2023 and 2024, according to Copernicus data released July 1. The successive years of records suggest warming is compounding—not cycling. Scientists had forecast strong El Niño conditions; what the data shows is that anthropogenic warming and El Niño's natural pulse are reinforcing each other, not simply overlapping. That distinction shapes climate policy urgency.