Grid with estimated yearly reference evapotranspiration with a spatial resolution of 10 arc minutes. The dataset contains average values for global land areas, excluding Antarctica, for the period 1961-1990. The dataset has been prepared according to the FAO Penman - Monteith method with limited climatic data as described in FAO Irrigation and Drainage Paper 56. The dataset consists one ASCII-grid with yearly data in mm/year. ASCII-grids with mean monthly data in mm/day * 10 are also available as described in the associated resources of this metadata.

Grid with average Wet Day Frequency (rain days per month) for the period 1961-1990. This dataset is constructed from observations, backed with synthetic data derived from precipitation. Source: New, M., Lister, D., Hulme, M. and Makin, I., 2002: A high-resolution data set of surface climate over global land areas. Climate Research 21:1-25