In the course of ongoing analysis of CHIRPS version 1.8, we found some irregularities in and around Tanzania, especially with respect to trends. We have determined that the cause of the errors were a subset of station data from a particular source. This problem is spatially limited to Central and Northern Tanzania and up to several hundred kilometers into the neighboring countries of Democratic Republic of Congo, Rwanda, Burundi, Uganda and Kenya. This problem is limited to the time period before 2013. All CHIRPS data after January 2013 and outside the areas identified above are unaffected.
This issue will be fixed and a new version of CHIRPS will be released as soon as possible. The next version will benefit from recently acquired station data from around the world as well as several improvements to the CHIRPS processing algorithm.
We thought it important to inform you of this issue now to minimize the effects in your ongoing research and analysis. We apologize for any difficulty this may cause.
As always, feedback is welcome.