HadCRUT5 Initial Release: HadCRUT.5.0.0.0

The data for HadCRUT.5.0.0.0 is available from this page. The most recent version HadCRUT5 is available from the HadCRUT5 versions page.

The HadCRUT5 near surface temperature data set is produced by blending data from the CRUTEM5 surface air temperature dataset and the HadSST4 sea-surface temperature dataset. Gridded data and regional time series for HadCRUT5 can be downloaded from this page.

All users are strongly encouraged to read the HadCRUT5 paper before using the data.

Version information

HadCRUT.5.0.0.0 is the version of HadCRUT5 that is presented in the HadCRUT5 paper (Morice et al., 2020) and includes data from the year 1850 to 2018. Updates to include more recent data are available from the HadCRUT5 versions page.

HadCRUT.5.0.0.0 analysis

The principal HadCRUT5 data set is a statistical analysis that extends coverage in data sparse regions and an improved analysis in observed regions. A non-infilled version of the dataset is also available.

HadCRUT5 analysis time series: ensemble means and uncertainties

The following files contain time series derived from the HadCRUT5 grids for selected regions. These 'best estimate' series are computed as the means of regional time series computed for each of the 200 ensemble member realisations. Time series are presented as temperature anomalies (deg C) relative to 1961-1990. The data are provided in NetCDF format.

Quoted uncertainties account for uncertainty described by the 200 ensemble members, together with an additional coverage uncertainty described in the HadCRUT5 paper that arises because the analysis is not globally complete. Details of uncertainty calculation can be found in the HadCRUT paper. Gridded data for the HadCRUT5 analysis ensemble members can be found later on this page.

HadCRUT5 analysis time series: ensemble members

The following time series are monthly and annual series for each ensemble member of the HadCRUT5 ensemble. The data are provided in NetCDF format.

Additional quoted uncertainties are estimates of uncertainty in global and regional averages with incomplete regional coverage. The additional uncertainties are identical for all ensemble members.

HadCRUT5 analysis gridded data: ensemble members

HadCRUT5 is presented as an ensemble data set in which the 200 ensemble members sample the distribution of the systematic component of observational uncertainty as well as analysis uncertainties described by the HadCRUT5 uncertainty model. These ensemble members are provided to allow users to more easily assess the sensitivity of their analyses to uncertainties in the observational data set. For more details please read the HadCRUT5 and HadSST4 papers.

The data are available in NetCDF format files.

HadCRUT5 analysis gridded data: additional fields

In addition to the HadCRUT5 ensemble, a mean file is available that contains fields of the mean anomaly from the 200 ensemble members in each grid box. The 200 member HadCRUT5 ensemble has been constructed to allow exploration of the sensitivity of scientific analyses to the estimated uncertainties. If only the mean is used it will not be possible to explore the sensitivity to these uncertainties.

HadCRUT.5.0.0.0 Non-infilled data

As well as the analysis, there is a non-infilled version of the data set which is of a similar character to HadCRUT4. Associated time series and grids can be found below.

HadCRUT5 non-infilled time series: ensemble means and uncertainties

The following files contain time series derived from the HadCRUT5 non-infilled grids for selected regions. These 'best estimate' series are computed as the means of regional time series computed for each of the 200 non-infilled ensemble member realisations. Time series are presented as temperature anomalies (deg C) relative to 1961-1990. The data are provided in NetCDF format.

Quoted uncertainties account for uncertainty described by the 200 ensemble members, together with additional uncertainty information that comprises uncertainties associated with measurement and sampling error, and uncertainties associated with large scale sampling. Gridded data for the HadCRUT5 non-infilled ensemble members can be found later on this page.

HadCRUT5 non-infilled time series: ensemble members

The following time series are monthly and annual series for each ensemble member of the non-infilled HadCRUT5 ensemble. The data are provided in NetCDF format.

Additional quoted uncertainties are estimates of uncertainty in global and regional averages with incomplete regional coverage as well as uncertainties from measurement and sampling errors. The additional uncertainties are identical for all ensemble members.

HadCRUT5 non-infilled gridded data: ensemble members

HadCRUT5 is presented as an ensemble data set in which the 200 ensemble members sample the distribution of the systematic component of observational uncertainty. These ensemble members are provided to allow users to more easily assess the sensitivity of their analyses to uncertainties in the observational data set. For more details please read the HadCRUT5 and HadSST4 papers.

The data are available in NetCDF format files.

HadCRUT5 non-infilled gridded data: measurement and sampling uncertainties

Measurement and grid box sampling uncertainties are not encoded into the HadCRUT5 ensemble members. Measurement and sampling uncertainties related to land and sea observations have different correlation structures and so are provided in separate files.

Measurement and sampling uncertainties describe the combination of basic measurement uncertainty and uncertainties in estimating average grid box anomalies from limited spatial sampling of temperatures within a grid box. Measurement and sampling uncertainties related to land observations have no spatial or temporal correlation structure.

Covariance matrices for HadCRUT5 are derived from the measurement and sampling uncertainty model of HadSST4. These describe correlated uncertainties between grid box anomalies where multiple boxes are observed by any given observing platform (e.g. a ship or drifting buoy) in a month as the platform moves from grid box to grid box. For HadCRUT5, cross covariance values of the HadSST4 measurement and sampling errors are weighted appropriately in coastal regions for grid boxes where anomalies are constructed from both land and sea observations. We strongly recommend that dataset users refer to the HadCRUT5 paper and the HadSST4 paper for detailed information about these uncertainties before making use of them in their studies.

HadCRUT5 Gridded data: additional fields

In addition to the HadCRUT5 ensemble a mean file is available that contains fields of the mean anomaly from the 200 ensemble members in each grid box. The 200 member HadCRUT5 ensemble has been constructed to allow exploration of the sensitivity of scientific analyses to the estimated observational bias uncertainties. If only the mean is used it will not be possible to explore the sensitivity to these uncertainties.

Maintained by: Colin Morice Last updated: 11/12/2020 Hosted by: Met Office Hadley Centre

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