The One-Degree Daily (IDD) technique is described for producing globally complete daily estimates of precipitation on a 1° × 1° lat/long grid from available observational data. The Threshold-Matched Precipitation Index (TMPI) is used to produce estimates in the 40°N–40°S latitude band, where 3-hourly infrared brightness temperatures (IR T_s) are compared with a threshold, and all "cold" pixels are given a single precipitation rate. This approach is adapted from the Geostationary Operational Environmental Satellite Precipitation Index, but the IR T_s threshold and conditional rain rate are set locally by month from Special Sensor Microwave Imager-based precipitation frequency and the Global Precipitation Climatology Project (GPCP) satellite-gauge (SG) combined monthly precipitation estimate. At higher latitudes, the IDD uses rescaled daily Television and Infrared Observation Satellite Operational Vertical Sounder (TOVS) precipitation. The frequency of rain days in the TOVS is scaled down to match that in the TMPI at data boundaries, and the resulting nonzero TOVS values are scaled locally to sum to the SG. The GPCP has approved the IDD as an official product, and data have been produced for 1997 through 1999, with production continuing a few months behind real time. Validation studies show that the mean absolute errors are relatively large but improve quickly when users perform time/space averaging according to their own requirements. The IDD provides flexibility in allowing users to compute these averages according to their needs while maintaining consistency with a standard larger-scale product (the GPCP SG).The One-Degree Daily (IDD) technique is described for producing globally complete daily estimates of precipitation on a 1° × 1° lat/long grid from available observational data. The Threshold-Matched Precipitation Index (TMPI) is used to produce estimates in the 40°N–40°S latitude band, where 3-hourly infrared brightness temperatures (IR T_s) are compared with a threshold, and all "cold" pixels are given a single precipitation rate. This approach is adapted from the Geostationary Operational Environmental Satellite Precipitation Index, but the IR T_s threshold and conditional rain rate are set locally by month from Special Sensor Microwave Imager-based precipitation frequency and the Global Precipitation Climatology Project (GPCP) satellite-gauge (SG) combined monthly precipitation estimate. At higher latitudes, the IDD uses rescaled daily Television and Infrared Observation Satellite Operational Vertical Sounder (TOVS) precipitation. The frequency of rain days in the TOVS is scaled down to match that in the TMPI at data boundaries, and the resulting nonzero TOVS values are scaled locally to sum to the SG. The GPCP has approved the IDD as an official product, and data have been produced for 1997 through 1999, with production continuing a few months behind real time. Validation studies show that the mean absolute errors are relatively large but improve quickly when users perform time/space averaging according to their own requirements. The IDD provides flexibility in allowing users to compute these averages according to their needs while maintaining consistency with a standard larger-scale product (the GPCP SG).