Easy-to-access-and-analyze geographic and climate data for Brasilian municipalities?

Could somebody point me towards geographical and climatic data for Brasil, ideally at the level of municipalities?

I already browsed the IBGE and other websites, but was not successful. I would like to use this data as input to economic analyses and ideally the data source would satisfy the following criteria: (i) already aggregated to the level of municipalities (ii) where municipalities are identified by IBGE code (iii) in Shapefile or Stata format (iv) free of charge and easy to get (download)