The planet’s oceans are at unprecedented temperatures for this time of year, breaking the all-time June record, according to new data, with alarming implications for global weather and marine life.
On June 21, average global sea surface temperatures reached 69.5 degrees Fahrenheit (20.86 Celsius), edging above the June record last set in 2024, according to data from Europe’s Copernicus Climate Change Service, which combines measurements from satellites, ships and buoys.
The record was echoed in another data set. Data from the Copernicus Marine Service, implemented by the non-profit Mercator Ocean International, found sea temperatures hit 69.38 Fahrenheit (21 Celsius) on June 21, beating the previous record last set in 2024 by 0.18 degrees Fahrenheit.
The abnormal heat has been driven by the onset of El Niño, a natural climate pattern characterized by unusually warm waters along the equatorial tropical Pacific Ocean. El Niño has only just started but it may intensify into one of the strongest in decades.
Layered underneath that is the human-driven climate crisis, which is also driving up temperatures. For decades, oceans have acted as the planet’s main heat sink, absorbing 90% of the excess heat produced by humans burning fossil fuels.
