I have temperature as a raster file and different ecoregions of a province as polygons. What I want to do is calculate the mean temperature per ecoregion.
I succeeded in doing this by Zonal Statistics which creates an output raster, but what I actually want, as I realized later, is I the temperature value per ecoregion. So how do I assign that value to the ecoregion?
I thought I can do zonal statistics as table and then join this table to the ecoregion. It does work but for some reason it does not calculate values for some of the ecoregions (1400 ouf of 7400 get null values). I tried to find a pattern in the ecoregions that didn't get assigned a value, so e.g if they were too small or have a too complicated shape or if they are at the edge of the province...but no..they are just randomly distributed.
Any ideas or something that I am missing?