The Met Office Hadley Centre's sea surface temperature data set, HadSST2, replaces the Met Office Historical Sea Surface Temperature dataset (MOHSST6) and is a monthly global field of SST (Sea Surface Temperature) on a 5 deg latitude by 5 deg longitude grid from 1850 to August 2013. The data are neither interpolated nor variance adjusted. The SST data are taken from the International Comprehensive Ocean-Atmosphere Data Set, ICOADS, from 1850 to 1997 and from the NCEP-GTS from 1998 to the present. HadSST2 is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and calculating a robust average of the resulting anomalies on a 5° by 5° degree monthly grid. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices before 1942. The uncertainties due to under-sampling have been calculated for the gridded monthly data as have the uncertainties on the bias corrections. This dataset include: - SST anomaly data (HadSST2_SST_1850on.txt.gz) - 1961-1990 Climatology (HadSST2_climatology_5x5_1961_1990.txt) - numbers of observations used to calculate the average (HadSST2_nobs_1850on.txt.gz) - Estimates on the measurement and sampling errors on the SST data (HadSST2_m_and_s_errors_1850on.txt.gz) - bias-adjusted data using bias adjustments which represent the 97.5 percent and 2.5 percent confidence levels of the estimated errors on the adjustments (HadSST2_97.5_pct_bias_1850on.txt.gz and HadSST2_2.5_pct_bias_1850on.txt.gz). - Files showing the correction applied to the data e.g.: HadSST2_bucket_correction_median.txt.gz - the corrections applied to the data 1850-1941 HadSST2_bucket_correction_2.5pc.txt.gz - the lower bound of the 95% confidence range of the uncertainties 1850-1941 HadSST2_bucket_correction_97.5pc.txt.gz - the upper bound of the 95% confidence range of the uncertainties 1850-1941 A 1 degree version of HadSST2 is also available. Data were provided by the Met Office Hadley Centre. Dataset was produced by the Hadley Centre in collaboration with ICOADS.

The longest available instrumental record of temperature in the world is now available at the BADC. The daily data starts in 1772. The mean, minimum and maximum datasets are updated monthly, with data for a month usually available by the 3rd of the next month. A provisional CET value for the current month is calculated on a daily basis. The mean daily data series begins in 1772. Mean maximum and minimum daily and monthly data are also available, beginning in 1878. Yearly files are provided from 1998 onwards. These historical temperature series are representative of the Midlands region in England, UK (a roughly triangular area of the United Kingdom enclosed by Bristol, Lancashire and London). The following stations are used by the Met Office to compile the CET data: Rothamsted, Malvern, Squires Gate and Ringway. But in November 2004, the weather station Stonyhurst replaced Ringway and revised urban warming and bias adjustments have now been applied to the Stonyhurst data after a period of reduced reliability from the station in the summer months. The data set is compiled by the Met Office Hadley Centre.

The longest available instrumental record of temperature in the world is now available at the BADC. The monthly data starts in 1659. The mean, minimum and maximum datasets are updated monthly, with data for a month usually available by the 3rd of the next month. A provisional CET value for the current month is calculated on a daily basis. The mean monthly data series begins in 1659. Mean maximum and minimum daily and monthly data are also available, beginning in 1878. These historical temperature series are representative of the Midlands region in England, UK (a roughly triangular area of the United Kingdom enclosed by Bristol, Lancashire and London). The following stations are used by the Met Office to compile the CET data: Rothamsted, Malvern, Squires Gate and Ringway. But in November 2004, the weather station Stonyhurst replaced Ringway and revised urban warming and bias adjustments have now been applied to the Stonyhurst data after a period of reduced reliability from the station in the summer months. The data set is compiled by the Met Office Hadley Centre.

CRUTEM (Climatic Research Unit TEMperature) is a gridded dataset of global historical near-surface air temperature anomalies over land at a monthly timescale. It is a collaborative product of the Climatic Research Unit at the University of East Anglia, the Met Office Hadley Centre and the National Centre for Atmospheric Science. CRUTEM also contributes the land air temperature station data to the global (land and ocean) temperature dataset called HadCRUT. CRUTEM5 is the fifth major version of the dataset, covering the time period from 1850, with a spatial resolution of 5° latitude by 5° longitude and a monthly-mean time resolution. The gridded temperature anomaly fields are based on a compilation of monthly-mean temperature observational records from weather stations. This compilation contains 10639 station records, but only 7983 records had the necessary coverage to be used for producing the gridded dataset. Anomalies are differences from average conditions in the 1961-1990 period. Hemispheric and global mean time series of land air temperature anomalies are also provided.

MOHSST, (Met Office Historical Sea-Surface Temperature) is a gridded dataset of sea-surface temperature anomalies covering the period 1856-2006. MOHSST has now been superceeded by HadSST2. We now recommend use of HadSST2 instead of MOHSST for all purposes. MOHSST is only still available in case it is needed for direct comparison with earlier work where MOHSST was used. MOHSST is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and averaging the resulting anomalies on a 5 by 5 degree monthly grid. Up to 1996 the measurements used are those in the U.K. Marine Data Bank; more recent years use data coming in through the GTS. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices, and the data are smoothed to reduce noise. The data were provided by the Met Office Hadley Centre.

The HadAT0 data are global radiosonde gridded temperature anomalies at standard levels (850, 700, 500, 300, 200, 150, 100, 50, and 30hPa) in the troposphere and in the lower stratosphere from 1958 to December 2002. This monthly timeseries are available on a 10 degree longitude by 5 degree latitude basis. This dataset supersedes the HadRT dataset. All values are anomalies relative to the monthly 1966-95 climatology.

The Met Office Hadley Centre produced the HadSLP1 dataset which replaces the Global Mean Sea Level Pressure (GMSLP) data sets, and is a unique combination of monthly globally-complete fields of land and sea pressure observations a 5 degree latitude-longitude grid from 1871 to 1998. The advantages of HadSLP1 over GMSLP2 are an improved land station data base, new interpolation scheme and the incorporation of local detail while safeguarding against random errors. Like GMSLP2, HadSLP1 was developed by Tracy Basnett and David Parker, in collaboration with R.J. Allan (previously at CSIRO and now at the Met Office) and M.J. Salinger (NIWA). Marine observations were taken from the Met Office Marine Data Bank (MDB) and from the NOAA Comprehensive Ocean-Atmosphere Data Set (COADS) (Woodruff et al, 1987). The MDB data were given priority in the blend, which is described in Basnett and Parker (1997). Land observations are a combination of data obtained from CSIRO (Australia), NIWA (New Zealand), CRU (University of East Anglia), GHCN, and operationally-received "CLIMAT" messages. The latter were used mainly for updating station series and for the Arctic. HadSLP1 pressures are reconstructed using a reduced-space optimal interpolation procedure, followed by superposition of quality-improved gridded observations onto the reconstructions to restore local detail.

The HADRT2.2u data are global monthly fields of radiosonde temperature anomalies at standard pressure levels on a 10 degree latitude by 20 degree longitude grid from 1958 to 2000. Anomalies are calculated with respect to 1971-1990 climatology. Anomalies are available for 9 standard levels (850, 700, 500, 300, 200, 150, 100, 50, 30hPa) as well as tropospheric (850 - 300hPa) and stratospheric (150 - 30hPa) averages. The data are degree Celsius anomalies from 1970-1990 means. Anomalies are calculated for each of about 200 sonde stations worldwide and grid values derived from these. HADRT2.2u are as HADRT2.2 but created from HADRT2.0. This dataset has been superseded by the HadAT dataset also available from CEDA.

The fully Global Mean Sea-Level Pressure (GMSLP) dataset, was developed in collaboration with CSIRO (Scientific and Industrial Research for Australia), Australia and NIWA (National Institute of Water and Atmospheric Research), New Zealand. It is an historical, 5 deg. x 5 deg. gridded monthly dataset covering the period 1871-1994. The Met Office Hadley Centre recently produced the HadSLP1 dataset which replaces the Global Mean Sea Level Pressure (GMSLP) data sets, and is a unique combination of monthly globally-complete fields of land and sea pressure observations a 5 degree latitude-longitude grid from 1871 to 1998.

MOHMAT, (Met Office Historical Marine Air Temperature) is a gridded dataset of marine air temperature anomalies covering the period 1856-2006. The current version of the dataset is MOHMAT4, which is described in reference below (under Doc tab). MOHMAT is produced by taking in-situ measurements of MAT from ships and buoys, rejecting measurements which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and averaging the resulting anomalies on a 5 by 5 degree monthly grid. Note that only night-time data are used, because day-time data are corrupted by heat island effects. Up to 1996 the measurements used are those in the U.K. Marine Data Bank; more recent years use data coming in through the GTS. MOHMAT is no longer updated. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in ship deck heights and various unusual operational practices, and the data are smoothed to reduce noise. The data are provided by the Met Office.