How to combine raster (with daily precipitaition data) to recieve monthly values

Discussion created by helena83 on May 3, 2011
Latest reply on May 3, 2011 by timothy_hales-esristaff

I'm very new to ArcGIS and I have run into the following problem. I have 30 raster files where every pixel has a certain precipitation value (TRMM). I would need to calculate the total precipitation for a certain area of the raster, i.e. I could need to find a way to calculate the values for each pixel and combine them to one raster that shows the total value. How can I do this?

I tried with combining the raster layers (spatial analyst-local-combine) but it doesnt give a correct answer.

I hope someone of you can help me out! thanks!