Sea Surface Temperature (SST), approx 5 x 8 x 30" 
Embroidery on silk.

The sea surface is the boundary between the ocean and atmosphere. Sea surface temperature (SST) can be used to understand the flows of energy between the two and hence the role of the oceans in shaping the weather and climate. Records of SST, using observations made from ships, go back to the mid-19th century and are some of the longest instrumental records available for understanding the climate. Since the early 1980s, there have also been measurements from satellites and bouys.

SST patterns influence key elements of the climate system, such as atmospheric circulation, rainfall patterns and tropical cyclones. They also form a key part of the datasets used to estimate global temperature change. SST is also important for forecasting at a range of timescales from hours to years ahead. Marine heatwaves, ocean fronts and regions of upwelling can all be monitored using measurements of SST.

The average sea surface temperatures (SSTs) over the extrapolar ocean (60 degrees S-60 degrees N) has increased markedly since records began in 1850. During the second half of the 19th century, the SST was relatively stable. During the first two decades of the 20th century, there was a period of cooling, followed by a period of warming during the 1930s and 1940s. There was little overall change from the 1950s to the mid-1970s. In the late 1970s, the SST abruptly started to rise and this warming continues. Between the late 19th century (1880-1900) and the last five years (2019-2023), the average SST over the extrapolar ocean has increased by about 0.9 degrees Celsius (1.6 degrees F).

Annual mean sea surface temperature anomalies in this graph are relative to the average for the 1991-2020 reference period. More information is at the Copernicus Climate Change Service webpage about Sea Surface Temperature (SST).

Other oil can graphs are here.