Monthly Meteorological Observations in Uruguay from INIA/GRAS Experimental Stations

The data are here.

The dataset includes the following variables:
Max, min, mean temperature (Celsius)
Relative Humidity (%)
Precipitation (mm/day)
Pan evaporation (mm/day)
Wind (km/day)
Hours of Sun (hrs/day)
Potential Evapotranspiration (mm/day)

NOTE: There appears to be erroneous data for Las Brujas. The pan evaporation and potential evapotranspiration data are identical for the time period Jul 1974 - Jun 1987.

More information about the Instituto Nacional de Investigación Agropecuaria (INIA) and the Grupo de Agroclima y Sistemas de Información  (GRAS) can be found  here.