GPCP Version 2.1 Combined Data Sets
X axis: whole world in 144 2.50° steps, first point at 1.25° E, last point at 358.75° E
Y axis: regular grid with 72 -2.50° steps, first point at 88.75° N, last point at 88.75° S

Monthly data available from Jan1979 to Jun2009 ( 366 months)
Variable prcp (precipitation) in mm/day
The associated land/sea mask is available for some operations

Get grid points, average area or generate subset

Latitude:	°N - °N
Longitude:	°E - °E
Boundaries:	halfway grid points interpolated
Make:	average set of grid points subset of the field
Demand at least:	% valid points in this region
Considering:	everything land points sea points show/hide more only land points only sea points not land points not sea points

Create a field with lower time resolution

New time scale:	annual (Jul-Jun) annual (Jan-Dec) seasonal monthly 10-daily 5-daily daily
New variable:	mean sd sum sum above sum below number min time of min max time of max first time last time of precipitation
Threshold:	no cut less than greater than mm/day percentile normal 1971-2000
Minimum:	% valid data

Construct a statistical forecast model from this field

Please consider downloading this field from the authoritative site.

If you really want to get it here, GPCP v2.1 precipitation is available as GrADS .ctl and gzipped .dat files (size 14.7129 MB)
Alternatively, you can generate a gzipped netCDF file of the same size.