Fast forward 2 days and the opportunity came up. Lo and behold, a Map of Reference Evapotranspiration built in Excel!
- Read data file into Excel (skip top rows with metadata), make sure to delimit correctly so that each value is in a column.
- Select ALL cells (Ctrl+A twice)
- Make column width same as row width
- With all selected, add a conditional formatting based on value.
Download the whole excel file here:
Based on FAO data