WorldClim is a free global climate layer dataset (climate grids) with approximately 1-kilometer spatial resolution, created and maintained by researchers at the University of California, Berkeley.
The data can be used for mapping and spatial modeling in a GIS or with other software programs.
More:
- Download current, past and predicted data: http://www.worldclim.org/download
- Access the download map where you can download only data for your area of interest: