Jennifer L. Koss, director of the NOAA Coral Reef Conservation Program, explains how the recent marine heat wave in portions of the Florida Keys has affected the coral and whether the coral has been able to rebound. Feb. 21, 2024.
ROME – The Mediterranean Sea is on track to potentially surpass its all-time highest recorded temperature, with large portions of the basin estimated to be between 5- and 10-degrees Fahrenheit above average, with even locally greater anomalies.
According to satellite data, sea surface temperatures throughout the region have been consistently breaking records through the month of June.
Most readings are registering in the mid to upper 70s Fahrenheit, and with the hottest months of the season still to come, there appears to be little in store to immediately reverse the warming trend.
The warmest average sea surface temperature for the Mediterranean was set just last year, when the basin reached a stunning 84 degrees Fahrenheit in August 2024, surpassing the previous record set in 2023, according to Europe’s Copernicus Marine Service.
Mediterranean Sea extreme warmth map
(Copernicus Marine Service / FOX Weather)
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Extended marine heatwaves are known to damage coral reef ecosystems, and while the Mediterranean Sea does not have extensive reefs compared to the tropics, biologists say it is home to unique coral formations and other marine habitats.
In addition to ecological risks, the warming sea surface is influencing weather patterns across Southern Europe and Northern Africa.
Weather observation sites have recorded elevated dew points in recent days, with some areas reaching the mid-70s Fahrenheit – levels of humidity typically seen in more tropical climates such as the United States’ Gulf Coast.
This level of added moisture can dramatically increase the heat index and make it harder for the human body to cool down through evaporation.
Studies estimate that just over 20% of households across Europe have access to air conditioning, which can make any heat wave oppressive.
Elevated sea surface temperatures in the Mediterranean are not just an isolated phenomenon – it is part of a larger global trend, with record warmth observed in most ocean basins over the past few years.
Many climatologists attribute the long-term warming to climate change, while others point to more regional oscillation patterns as contributing factors.
SST Anomaly map as of June 23, 2025.
(ClimateReanalyzer.org / FOX Weather)
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So what does this mean for the Atlantic hurricane season?
At face value, a persistently warm subtropical zone, such as the current Mediterranean setup and nearby waterways, can suppress tropical cyclone formation in the Main Development Region (MDR) of the Atlantic by decreasing atmospheric instability.
At the same time, it can also lead to tropical activity in more unusual northern latitudes, outside the classic storm formation zones.
Forecasters will be watching closely to see whether the current anomalies in the Mediterranean Sea migrate more southwestward, which could align with more traditional water temperature patterns.
2003 SST Global Anomalies
(NOAA)
A similar setup occurred in 2003, when a boiling Mediterranean was paired with a more lukewarm tropical Atlantic early in the season, but sea temperatures eventually transitioned weeks later, warming the MDR and leading to several long-track Cape Verde hurricanes.
Whether the 2025 hurricane season follows a similar pattern remains to be seen, but the impacts of the latest Mediterranean heat wave will be monitored for impacts locally and around the globe.
