Global Oceans Bulletin of the American Meteorological Society

El Niño ebbed in early 2024, reaching neutral status in May and crossing the threshold into La Niña conditions in December. The global average annual sea surface temperature was 0.06°C above the previous record set in 2023. Marine heatwaves in 2024 were, as in 2023, more widespread, long-lived, and severe than in previous years. From 2023 to 2024, ocean heat content from 0 dbar to 2000 dbar increased at a rate equivalent to ∼1.5 W m−2 of heat applied over the ocean surface, and global sea level increased by 4.6 (±1.4) mm, both reaching record-high levels in 2024. Maps of air-sea flux data estimate that the oceans absorbed carbon at a rate of ∼2.7 Pg C yr−1 in 2024, which was below the 2014-23 average of ∼3.7 Pg C yr−1.