SST data: HadiSST v1.1

The Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) is a combination of monthly globally complete fields of SST and sea ice concentration for 1871-present. This page focuses on the SST data; see the separate page for discussion of HadISST sea ice. HadISST uses reduced space optimal interpolation applied to SSTs from the Marine Data Bank (mainly ship tracks) and ICOADS through 1981 and a blend of in-situ and adjusted satellite-derived SSTs for 1982-onwards. The "bucket correction" was applied to SSTs for 1871-1941. SSTs in boxes partially covered by sea ice were estimated from statistical relationships between SSTs and sea ice concentrations. SSTs were assigned a fixed value (-1.8°C) for areas with sea ice cover of greater than 90%. HadISST is primarily intended to be used as boundary conditions for atmospheric models. Version 1.1 is the current version.

Key Strengths

Global, spatially complete data set useful as boundary conditions for AMIP experiments

Key Limitations

Does not account for changes in SST measurement practices post-1941; suspected cold bias since the late 1990s

Sparse data input in the polar regions; especially in the Southern Ocean. SSTs in the high polar seas also depend on the sea ice analysis, which has its own documented problems (see separate sea ice page)

Non-robust trends have been identified; for example equatorial Pacific trends over the 20th Century may be misrepresented due to interpolation methods (Deser et al., 2011) and/or representation of ENSO variance (Solomon and Newman, 2012)

Please cite data sources, following the data providers' instructions

Suggested Data Citation

Met Office, Hadley Centre. HadISST 1.1 - Global sea-Ice coverage and SST (1870-Present), [Internet]. NCAS British Atmospheric Data Centre, 2006, Date of citation,. Available from http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_hadisst
NCAR RDA: "The data for this study are from the Research Data Archive (RDA) which is maintained by the Computational and Information Systems Laboratory (CISL) at the National Center for Atmospheric Research (NCAR). NCAR is sponsored by the National Science Foundation (NSF). The original data are available from the RDA (http://rda.ucar.edu) in dataset number ds277.3."
Rayner, N. A.; Parker, D. E.; Horton, E. B.; Folland, C. K.; Alexander, L. V.; Rowell, D. P.; Kent, E. C.; Kaplan, A. (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, J. Geophys. Res., Vol. 108, No. D14, 4407 10.1029/2002JD002670

Dataset DOIs

None

Hosted Climate Index Files

None

Data Access

Usage Restrictions

None

Cite this page

Acknowledgement of any material taken from or knowledge gained from this page is appreciated:

National Center for Atmospheric Research Staff (Eds). Last modified 2022-09-09 "The Climate Data Guide: SST data: HadiSST v1.1.” Retrieved from https://climatedataguide.ucar.edu/climate-data/sst-data-hadisst-v11 on 2025-08-28.

Citation of datasets is separate and should be done according to the data providers' instructions. If known to us, data citation instructions are given in the Data Access section, above.

Acknowledgement of the Climate Data Guide project is also appreciated:

Schneider, D. P., C. Deser, J. Fasullo, and K. E. Trenberth, 2013: Climate Data Guide Spurs Discovery and Understanding. Eos Trans. AGU, 94, 121–122, https://doi.org/10.1002/2013eo130001