Sea temperature and salinity trends

We collect data on sea-surface temperature (and sometimes salinity) at a number of coastal sites around England and Wales, some operated by volunteers, some operated by local councils and some associated with power stations. The longest time-series include those from Eastbourne (1892 - present), Dover (1926 - present) and Port Erin, Isle of Man (1903 -  present) although most time series began in the 1960s or 1970s.

Data points are usually presented as monthly mean sea surface temperature, in tabular format and are updated on an annual basis (data up to 2012 is currently provided). Efforts are underway to modernise some aspects of this network, and in particular to try to re-start time series that have halted in recent years, making use of electronic data loggers that are deployed once or twice a year (for example in Lowestoft harbour).

The data available through our website represents an updated version of that presented in the report by Joyce et al. (2004) (PDF,2.63 MB) but also Norris (2001) (PDF, 617 KB) and Jones and Jeffs (1991) (PDF, 4.22 MB). As well as providing information on temperature at fixed coastal sites, offshore data is also available from the ferry route between Harwich (or Felixstowe) and Rotterdam. Additional 'historic' data series are currently being digitised such as the ferry route between Southampton and Saint Malo (1910 to 1964) and from various offshore light-ships (e.g. Smith's Knoll, 1911 to 1988). Surface temperature and salinity time-series were assembled by Ellett and Jones (1994) (PDF, 155 KB) from the Rockall Channel, spanning the period 1948 to 1992.


The author wishes to thank the following Cefas observers for their dedication over the years:

  • Mr M Eynon
  • Mr T Wright
  • Mr S Billing
  • Mr W Browning
  • Mr A Putt
  • Mr E Jones
  • Mr P Jackson
  • Mr G Bullimore
  • Mr P Henneker
  • Mr A Barclay
  • Mr D Knapp
  • Mrs J Stannard
  • Mr B Bevan
  • Mr J Powell
  • Mr H Philcox
  • Capt. P Tambling
  • Mr M Hellyer
  • Mr R Roch
  • Mr C Fisk
  • Capt. M Kenyon

In addition, measurements have been obtained from other sources, such as National Power, CEGB, British Energy Generation UK Ltd., BNFL, National PC, Powergen UK, Eastbourne Borough Council, Bournemouth Borough Council, Scarborough Borough Council, Skomer Island National Nature Reserve and the University of Liverpool.

Grateful thanks to all these establishments who have freely given permission for their data to be included in this report.


Jones, S.R., and Jeffs, T.M., 1991. Near-surface sea temperatures in coastal waters of the North Sea, English Channel and Irish Sea. Data Rep., MAFF, Lowestoft, (24), 70pp.

Norris, S.W., 2001. Near-surface sea temperatures in coastal waters of the North Sea, English Channel and Irish Sea - Volume II. Data Rep., Cefas, Lowestoft, (40), 31pp.

Dickson, R.R., Dye S., and Meincke J., 2001. The NAO in winter 2001: early indications of a sharp return to NAO-Negative conditions. ICES WGOH, Reykjavik, Iceland, 19-21 March 2001.