Past (observed) climate and future climate scenario projections data that were produced as part of the UK climate projections 2009 (UKCP09) service. The data produced by the UK Met Office providing information on plausible changes in 21st century climate for the UK helping to inform on adaptation to a changing climate. A UKCP09 website provided climate information for the UK and its regions. Through the website user interface climate statistics over the UK could be calculated dynamically. The data that informs these calculations is made available here. UKCP09 provides future climate projections for land and marine regions as well as observed (past) climate data for the UK. Additionally a copy of the projections csv archive is provided. These are zip files of batch processed UKCP09 data outputs. The projections improve upon the previous climate projections (UKCIP 2002) by incorporating more recent scientific understanding, providing data at a higher spatial resolution and providing an approach to dealing with uncertainties through probabilistic projections.

The UK climate projections (UKCP09) comma separated value (CSV) archive consists of probabilistic data for various climate parameters. Two products are available: firstly, zip files of batch processed UKCP09 data outputs that were provided as an alternative to having to generate multiple requests on the UKCP09 website; and, secondly, additional products that were not available under from the UKCP09 website. These are provided as raw data files. List of products: 1. UK Probabilistic Projections of Climate Change over Land: Grouped by - variable and location and - variable and temporal average. 2. UK Probabilistic Projections of Climate Change over Marine Regions: Grouped by - emissions scenario, - location, - temporal average, - time period, - variable, - variable and location and - variable and temporal average. 3. Projections of Trend in Storm Surge for UK Waters: all data is grouped into one file. 4. Projections of Sea Level Rise for UK Waters: Grouped by - emissions scenario, - location and - emissions scenario and location. 5. Global average temperature change values for each time period and emissions scenario: - all cumulative distribution function (CDF) data in a single file - all sampled data in a single file. 6. UK Probabilistic Projections of Climate Change over Land conditioned by a given global average temperature change: Grouped by - probability level and - variable and probability level 7. Spatially Coherent Projections of UK Climate Change over Land: grouped by variable, temporal average and scenario The file naming convention is provided in the documentation.

The UK Climate Projections 2009 (UKCP09) projections of temperature from low, medium and high emissions scenarios' equivalent global temperature changes. They are probabilistic climate predictions based on families of runs of the Met Office Hadley Centre climate models HadCM3, HadRM3 and HadSM3, plus climate models from other climate centres contributing to IPCC AR4 and CMIP3. The equivalent changes in global temperatures are taken from three emissions scenarios: low (IPCC SRES: B1), medium (IPCC SRES: A1B), and high (IPCC SRES: A1FI). Each scenario provides estimates over seven 30 year period averages: 2010-2039, 2030s = 2020-2049, 2040s = 2030-2059, 2050s = 2040-2069, 2060s = 2050-2079, 2070s = 2060-2089, 2080s = 2070-2099. Temperature changes are given relative to 1961-1990.

The UK Climate Projections 2009 (UKCP09) probabilistic marine projections data are projections of a future climate with an associated probability. Monthly and annual data are provided for mean sea level pressure, temperature, precipitation and total cloud cover in 30 year averages (2010-2039, 2020-2049, 2030-2059, 2040-2069, 2050-2079, 2060-2089, 2070-2099). These projections provide an absolute value for the future climate (as opposed to giving values that are relative to a baseline period). A probabilistic climate projection is a measure of the strength of evidence in different future climate change outcomes. This measure is dependent on the method used, is based on the currently available evidence and encapsulates some, but not all, of the uncertainty associated with projecting future climate. The marine and coastal projections report contains further details (see linked documentation).

The UK climate projections 2009 (UKCP09) marine and coastal multi-level ocean projections provide detailed information on the potential future implications of climate change on the marine environment in UK waters. Marine parameters are provided for projections of changes in water temperature, salinity, currents and stability of the water column over a 12km marine grid, for the 30 year time period 2070-2099 (and the baseline period 1961-1990) for the medium emissions scenario (IPCC SRES: A1B). Note: The multi-level ocean projections are based on a single model simulation. In contrast to some other components of UKCP09 these are not probabilistic projections, meaning they do not quantify the range of future changes associated with modelling uncertainties or natural climate variability. More information about the variables and methodology (including assumptions and caveats) are given in Chapter 6 of the Marine & coastal projections report (see linked documentation).

The UK Climate Projections (UKCP09) probabilistic climate projections of climate change over land. These data consist of various meteorological parameters such as temperature, precipitation, surface pressure, humidity. The projections of future absolute climate that assign a probability level to different climate possibilities, the absolute values, percentage change relative to the observed climate (1961-1990) and percentiles of the parameter projections are provided over 30 year time periods over the projection period 2010-2099. The averaging periods provided are: 2010-2039, 2020-2049, 2030-2059, 2040-2069, 2050-2079, 2060-2089, 2070-2099. Data are provided over three aggregated areas, (1) a 25km grid over the UK, (2) administrative regions that are areas of the UK based on administrative boundaries and (3) river basins that are based on a division of the UK land area based on the Water Framework Directive River Basin Districts. In 2009 the first version of the UK probabilistic projections of climate change over land were provided. In 2013 an update was made to some of the files (version 2). Both versions of this data are made available here with the version 2 data being the most recent. These projections provides an absolute value for the future climate (as opposed to giving values that are relative to a baseline period). A probabilistic climate projection is a measure of strength of evidence in different future climate change outcomes. This measure is dependent on the method used, is based on the current available evidence and encapsulates some, but not all, of the uncertainty associated with projecting future climate. The climate projections report contains further details.

The UK climate projections 2009 (UKCP09) observed climate provides data for a range of climate variables (for example, temperature, pressure, vapour pressure, rainfall, snowfall, sunshine) over the climate averaging period 1961-1990. The observed data is provided over the UK at grid box resolutions of 25km and 5km. The observed data refers to data that has been directly measured and obtained in UK from a network of synoptic observations and weather stations. These data are commonly processed to convert irregularly spaced point observations to a regular grid. The observed climate data can be used both to explore past climate trends, to construct and validate climate models and to provide a baseline to construct climate differences.

UK Climate Projections 2009 (UKCP09) sea level rise data provides projections of changes in absolute sea level rise in waters surrounding the UK and changes in relative sea level for coastal areas, where the influence of land movements is considered (and data included here) over the period 1999-2099. Data are provided for three emissions scenarios: Low (IPCC SRES: B1), Medium (IPCC SRES: A1B), and High (IPCC SRES: A1FI). These projections also include a high risk, low probability scenario (known as the H++ scenario). The H++ scenario has been included to reflect the fact that there considerable uncertainties about the upper limit of absolute sea-level rise. This scenario relies, in part, on expert judgement and is designed to encourage users to think about thresholds of existing systems and the limits to adaptation. Note: Unlike some other components of UKCP09, the sea level projections are not probabilistic. They provide a frequency distribution of projections based on results from eleven models contributed to the IPCC Fourth Assessment Report. The model projections of sea level rise have not been weighted based on comparison with historical sea level observations, and are therefore treated as equally plausible. More information about the sea level rise methodology (including assumptions and caveats) is given in Chapter 3 of the Marine & coastal projections report.

The UKCP09 marine & coastal storm surge data provides projections of surge height for the linear trend, the 5th and 95th percentiles throughout the 21st Century for 2, 10, 20 and 50 year return period events (including statistical significance) over a 12km coastal grid. Data are available for a medium emissions scenario (IPCC SRES: A1B), to reflect some aspects of the uncertainty in modelling global and regional climate change eleven different variants of the Met Office Hadley Centre climate model HadCM3 were used to drive eleven corresponding variants of the HadRM3 regional model, which in turn drove the National Oceanography Centre storm surge model (POLCS3). Note: The projections do not cover all plausible future outcomes and unlike some other components of UKCP09, the storm surge height projections are not probabilistic, although a range is provided based on the assumption that the 11 simulations are equally likely. More information about the storm surge methodology (including assumptions and caveats) are given in Chapter 4 of the UKCP09 Marine & coastal projections report and the technical note on storm projections.

This dataset contains measurements of sea surface temperature (SST) (HadISST1.1). Dataset include monthly mean gridded (1deg grid), global SSTs from 1870 to October 2015. This product replaced the GISST/GICE (Global Sea Surface Temperature/Global sea-Ice content) data sets ended in February 2003. The SST data are taken from the Met Office Marine Data Bank (MDB), which from 1982 onwards also includes data received through the Global Telecommunications System (GTS). In order to enhance data coverage, monthly median SSTs for 1871-1995 from the Comprehensive Ocean-Atmosphere Data Set (COADS) (now ICOADS) were also used where there were no MDB data. The sea ice data are taken from a variety of sources including digitized sea ice charts and passive microwave retrievals. HadISST1 temperatures are reconstructed using a two stage reduced-space optimal interpolation procedure, followed by superposition of quality-improved gridded observations onto the reconstructions to restore local detail. The sea ice fields are made more homogeneous by compensating satellite microwave-based sea ice concentrations for the impact of surface melt effects on retrievals in the Arctic and for algorithm deficiencies in the Antarctic, and by making the historical in situ concentrations consistent with the satellite data. SSTs near sea ice are estimated using statistical relationships between SST and sea ice concentration. From May 2007 the data set of in situ measurements used in HadISST has changed. The MOHSST data set, which was previously used has been discontinued, and HadSST2 is now being used in its place. The two systems ran in parallel for several months prior to the changeover and no significant differences were seen. The data were provided by the Hadley centre (Met Office). Important Notes: On 13th March 2015: Users have noticed that there is a minor discontinuity at the dateline in HadISST1 SST fields starting in 1982. It appears to only affect gridcells just to the east of the dateline. Please note that this can affect estimates of the mean and variability of SSTs in HadISST1 when analysed across this region. On 3rd December 2010: The SSM/I satellite that is used to provide the data for the sea ice analysis in HadISST suffered a significant degradation in performance through January and February 2009. The problem affected HadISST fields from January 2009 and probably causes an underestimate of ice extent and concentration. It also affected ses surface temperatures in sea ice areas because the SSTs are estimated from the sea ice concentration. As of 3rd December 2010, the Met Office Hadley Centre has reprocessed the data from January 2009 to the present using a difference sea ice data source. This is an improvement on the previous situation but users should still note that the switch of data source at the start of 2009 might introduce a discontinuity into the record.