Seasonal heat content in the top half-mile of the ocean compared to the 1955-2006 average. Heat content in the global ocean has been above-average (red bars) since the mid-1990s. Graph by NOAA Climate.gov, based on data from NOAA NCEI.

Change in heat content in the upper 2,300 feet of the ocean from 1993-2021. Most places have gained heat (orange). Shading indicates changes were smaller than the range of natural variability. NOAA Climate.gov image, based on data from John Lyman.