The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global monthly precipitation dataset covering July 1987 through December 1995. The dataset combines precipitation estimates from low-orbit satellite microwave data, geosynchronous satellite infrared data, and rain gauge observations. It includes individual input fields, a combination of microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5° × 2.5° latitude–longitude global grids. Preliminary analyses show agreement with prior studies of global precipitation and extend prior studies of El Niño–Southern Oscillation precipitation patterns. At the regional scale, there are systematic differences with standard climatologies. The GPCP was established to address the problem of quantifying global precipitation distribution, which is complicated by the lack of a single estimate with sufficient coverage and accuracy. The GPCP's goal is to provide monthly mean precipitation data on a global 2.5° × 2.5° grid for the period 1986–2000. The general approach is to combine precipitation information from each source into a final merged product, taking advantage of the strengths of each data type. The microwave estimates are based on SSM/I data from DMSP satellites, while infrared estimates are obtained from geostationary satellites. Gauge data are assembled by the GPCC. The GPCP has developed an analysis procedure to blend the various estimates into a global gridded precipitation field. The current procedure is based on Huffman et al. (1995) and has been used to produce the GPCP Version 1 Combined Precipitation Data Set. The primary product is a combined observation-only dataset, which is useful for climate model validation, hydrological and climate monitoring, and diagnostic studies. Gaps in coverage at high latitudes will be addressed in a future release. The GPCP Version 1 dataset includes individual dataset summaries, error estimates, and combination methods. The dataset includes rain gauge analysis, microwave estimates, and infrared estimates. The rain gauge analysis uses SPHEREMAP interpolation to convert station data to regular grid points. Microwave estimates are based on SSM/I data, with two algorithms for ocean and land regions. Infrared estimates are based on geostationary satellite data, with a technique relating cold cloud-top area to rain rate. The GPCP combination method uses the strengths of each input dataset to produce merged global monthly precipitation fields. The method includes a microwave/IR calibration ratio, a multisatellite estimate, and a satellite/gauge estimate. The multisatellite estimate is formed from three satellite sources, while the satellite/gauge estimate is computed in two steps. The resulting precipitation products allow users to choose different products based on their requirements. The GPCP Version 1 dataset has been validated against rain gauge analyses and showsThe Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global monthly precipitation dataset covering July 1987 through December 1995. The dataset combines precipitation estimates from low-orbit satellite microwave data, geosynchronous satellite infrared data, and rain gauge observations. It includes individual input fields, a combination of microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5° × 2.5° latitude–longitude global grids. Preliminary analyses show agreement with prior studies of global precipitation and extend prior studies of El Niño–Southern Oscillation precipitation patterns. At the regional scale, there are systematic differences with standard climatologies. The GPCP was established to address the problem of quantifying global precipitation distribution, which is complicated by the lack of a single estimate with sufficient coverage and accuracy. The GPCP's goal is to provide monthly mean precipitation data on a global 2.5° × 2.5° grid for the period 1986–2000. The general approach is to combine precipitation information from each source into a final merged product, taking advantage of the strengths of each data type. The microwave estimates are based on SSM/I data from DMSP satellites, while infrared estimates are obtained from geostationary satellites. Gauge data are assembled by the GPCC. The GPCP has developed an analysis procedure to blend the various estimates into a global gridded precipitation field. The current procedure is based on Huffman et al. (1995) and has been used to produce the GPCP Version 1 Combined Precipitation Data Set. The primary product is a combined observation-only dataset, which is useful for climate model validation, hydrological and climate monitoring, and diagnostic studies. Gaps in coverage at high latitudes will be addressed in a future release. The GPCP Version 1 dataset includes individual dataset summaries, error estimates, and combination methods. The dataset includes rain gauge analysis, microwave estimates, and infrared estimates. The rain gauge analysis uses SPHEREMAP interpolation to convert station data to regular grid points. Microwave estimates are based on SSM/I data, with two algorithms for ocean and land regions. Infrared estimates are based on geostationary satellite data, with a technique relating cold cloud-top area to rain rate. The GPCP combination method uses the strengths of each input dataset to produce merged global monthly precipitation fields. The method includes a microwave/IR calibration ratio, a multisatellite estimate, and a satellite/gauge estimate. The multisatellite estimate is formed from three satellite sources, while the satellite/gauge estimate is computed in two steps. The resulting precipitation products allow users to choose different products based on their requirements. The GPCP Version 1 dataset has been validated against rain gauge analyses and shows