HadCRUT is a gridded dataset of global historical surface temperature anomalies, relative to a 1961-1990 reference period. Data are available for each month since January 1850, on a 5 degree grid. The gridded data are a blend of the CRUTEM land-surface air temperature dataset and the HadSST sea-surface temperature (SST) dataset. The dataset is presented as an ensemble of 100 dataset realisations that sample the distribution of uncertainty in the global temperature record.

This is the HadCRUT.4.4.0.0 version of the HadCRUT4 data. Data are available for each month since January 1850, on a 5 degree grid. The gridded data are a blend of the CRUTEM4 land-surface air temperature dataset and the HadSST3 sea-surface temperature (SST) dataset. The dataset is presented as an ensemble of 100 dataset realisations that sample the distribution of uncertainty in the global temperature record. The ensemble median is provided and is provided as r0. Error covariance information are available from the Met Office (see the link to the HadCRUT4 homepage in Docs) To keep up to date with updates, news and announcements follow the HadOBS team on twitter @metofficeHadOBS. References: When using the dataset in a paper you must cite the following paper (see Docs for link to the publication) and this dataset (using the "citable as" reference) : Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones (2012), Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset, J. Geophys. Res., 117, D08101, doi:10.1029/2011JD017187

This is the HadCRUT.4.5.0.0 version of the HadCRUT4 data. Data are available for each month since January 1850, on a 5 degree grid. The gridded data are a blend of the CRUTEM4 land-surface air temperature dataset and the HadSST3 sea-surface temperature (SST) dataset. The dataset is presented as an ensemble of 100 dataset realisations that sample the distribution of uncertainty in the global temperature record. The data consist of 100 ensemble members and the ensemble median, each are available as a separate file where the fourth component of the filename denotes the ensemble member or median. In addition, the variance information is provided under the name uncorrelated. Full error covariance data are available from the Met Office (see the link to the HadCRUT4 homepage in Docs) To keep up to date with updates, news and announcements follow the HadOBS team on twitter @metofficeHadOBS. References: When using the dataset in a paper you must cite the following paper (see Docs for link to the publication) and this dataset (using the "citable as" reference) : Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones (2012), Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset, J. Geophys. Res., 117, D08101, doi:10.1029/2011JD017187