NIFS announced that the average sea surface temperature (SST) in Korean waters once again hit new record high in 2024, surpassing 2023 which had previously held the record, according to the analysis that NIFS conducted based on the data from its fisheries research vessels (R/Vs) and satellite observations. 

     * NIFS has provided the data and information from the NIFS serial oceanographic observation stations bimonthly (since the 1960s) and daily from satellite observation (since the 1990s). 

The R/Vs observation showed that the average Korean SST a year was 18.74℃ in 2024, which was the highest values in recent 57 years (from 1968 to 2024), a 0.65℃ increase from 2023 level (18.09℃) that was an all-time high record.

All sea areas recorded the highest water temperature, 18.84℃, 17.12℃, and 20.26℃ for the East Sea, the West Sea, and the South Sea, respectively. 

     * 0.65℃ increase from the previous year (2023, 18.09℃), 1.62℃ increase from the average year (30-year average from 1991 to 2020, 17.12℃)                                                                                     ** By sea area (average year/deviation): the East Sea (17.08℃/1.77℃ increase); the West Sea (15.30℃/1.82℃ increase); and the South Sea (18.99℃/1.26℃ increase)

Moreover, satellites observed that the average SST of the North Western Pacific Sea was 21.11℃, the highest values in recent 25 years (from 2000 to 2004).

By sea area, all reached a record high, 16.31℃ for the East Sea, 16.80℃ for the West Sea, and 21.72℃ for the South Sea. 

     * 0.89℃ increase from the previous year (2023, 20.22℃), 1.55℃ increase from the recent 20 years (20-year average from 2001 to 2020, 19.56℃)                                                                                 ** By sea area, (recent 20-year average/deviation): the East Sea (14.82℃/1.49℃ increase); the West Sea (15.18℃/1.63℃ increase); and the South Sea (20.01℃/1.71℃ increase) 

The reasons behind the remarkably high SST in Korean waters last year were likely to be the accelerated global warming, extreme heat waves persisting between summer and fall around the Korean peninsula, and an increased supply of heat by the inflow of current from low latitude (5~20˚N) near equator. 

On January 10, 2025, the World Meteorological Organization (WMO) issued a press release that it confirmed 2024 as warmest year on record at about 1.55℃ above pre-industrial level. In addition, WMO announced that the global sea surface temperature (SST) and the ocean heat content (OHC) also had the highest record. 

     *The Ocean Heat Content (OHC), as an indicator of ocean warming, is a quantity that describes the thermal energy stored in a volume of the ocean. It is measured in terms of the amount of heat energy (in joules) absorbed by a unit mass of seawater.