In other words, he wouldn't actually use it except when filling in forms? Yeah, why not? Seems to have as many bleak associations as positive ones - save for a rainy day, into each life a little rain must fall, rain, rain, go away - but if it's meaningful to you it'll be meaningful to him too. Which is surely the point?
Botswana is mostly desert and semi-desert.
Rain, understandably, is very important to the people there, and their currency is called the Pula, which means '
Rain'. In the form 'Mapula' (same meaning; pronounced muh POO luh) it is used as a girl name.