Hi, do you use which database? Radar or Weather Stations? If it is a season, why do not you do the water balance calculations first and then interpolate the results?

Thank you Fernando Coelho Eugenio

I used IMD grid rainfall and temperature data. I agree with you that first calculate water balance for 14 stations and then make a interpolation applying IDW or kriging method using ArcGIS. Can I used "Raster Calculator" for calculation of water balance?

Hi, I'm not sure about your data conditions. The Raster calculator from ArcGIS a great tool to perform calculations using raster layers, constants and conditionals. If you know the equations for one site you can use this in similar way for a full raster layer.

There are some toolboxes in web, i.e. this toolbox https://people.ohio.edu/dyer/water_balance.html that you can try. Sorry, I did'nt use this toolbox by long time (since ArcGIS 9), so I dont know how is working now.

There are other options out of ArcGIS. For example, iterating using python os R over cell values in a specialized software like https://wwwbrr.cr.usgs.gov/projects/SW_MoWS/Thornthwaite.html.

My best for your computes!

Thanks Gabriel Vicente Gaona

I will try to apply toolbox suggest by you.

Thanks for your valuable guidance and links.