I was hoping to build an automated rainfall harvesting check on the top of the open access weatherninja rainfall data.
I downloaded the 2014 data for Gowerton, to compare it to a dataset I had from Natural Resouces Wales for the same area. Their data is trusted for this lcoation so it is a good baseline. There’s a large (35%+) difference, with renewables ninja underestimating the rainfall. https://github.com/cromlyngames/Cardiff_rain_storage/blob/master/Gowerton_2014_RainfallComparision.xlsx
There may be a difference of 1km between the sites but this would not explain the difference in rainfall. Any idea what the source of the difference might be and how I can correct for it?