About
The datasets have been developed in conjunction with Hadley Centre of the UK Met Office. Hosted by the Climate Research Unit at the University of East Anglia. From website:
HadCRUT3 combined land and marine [sea surface temperature (SST) anomalies from HadSST2, see Rayner et al., 2006] temperature anomalies on a 5° by 5° grid-box basis
Data is from 1961 to 2008.
See also:
Format
Available for download in Zipped ASCII or NetCDF (see project page and wikipedia page).
Access/re-use
Data is open. Attribution must be given. Main Climate Research Unit data page says:
The various datasets on the CRU website are provided for all to use, provided the sources are acknowledged. Acknowledgement should preferably be by citing one or more of the papers referenced on the appropriate page. The website can also be acknowledged if deemed necessary. CRU will endeavour to update the majority of the data pages at timely intervals although this cannot be guaranteed by specific dates.