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I am exporting a CHIRPS precipitation raster from Google Earth Engine. This is part of a larger collection of data that I'll be exporting, but I'm just inspecting one image at the moment.

I've exported a CHIRPS product that was recorded on January 15, 2017 just west of Mount Kenya (shown below) and I've brought it into ArcGIS to inspect it further.

enter image description here

I know that the total rainfall for this area on January 15, 2017 was 173.62mm, as this is the value returned from Google Earth Engine.

However, if I convert the raster to a numpy array and sum up the array values, I get 115,540.41 as the sum of all pixels. Here is the few lines of code used to create and sum the array:

inRas = arcpy.Raster("\\Jan152017MtKenya.tif")
arr = arcpy.RasterToNumPyArray(inRas, nodata_to_value=0)
arr.sum()

Again, if I were to use the Identify tool in ArcGIS to get the cell value, each cell value would return the precipitation value that I would expect. It's only when I convert to a numpy array that the cell values appear much larger than I'm expecting.

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