Sea temperature charts
Sea surface temperature
Is the is the water temperature close to the surface.
display the temperature of the water at the sea surface.
was how this data was traditionally gathered (ie. using a thermometer!) with buoys and weather ships.
Remote sensing with satellites
is how most temperature data is measured these days. The area a satellite scans in two minutes would take a ship travelling at 10 knots 10 years to cover.
Sea surface temperature (°C), from UK Met Office
Date of chart: 25 May 2013
Sea surface temperature (°C), from Cologne University Meteorology
Date of chart: 24 May 2013
North Atlantic sea surface temperature, from Oceanweather
Mid Atlantic sea surface temperature, from Oceanweather
European sea surface temperatures, from Oceanor
Worldwide sea surface temperatures, from Unisys Weather
This clearly shows global phenomenon such as El Nino, and the warm waters of the Gulf Stream flowing from the US towards Europe.