Development of high-resolution gridded datasets of monthly temperature in Portugal

High-resolution gridded datasets of monthly minimum and maximum temperature with 0.2˚ × 0.2˚ spatial resolution (approximately 20 km) are generated for Portugal covering the period 1950–2003. At the purpose of their application in a wide range of climatological and hydrological studies over Portugal and the Iberian Peninsula, the time period and the spatial resolution are intentionally set to be the same of the daily gridded datasets recently developed for Portugal (PT02, only precipitation) and Spain (Spain02, precipitation, and minimum and maximum temperature). The Ordinary Kriging method is used to produce the temperature fields interpolated from 36 meteorological stations regularly distributed over Portugal. The performance and accuracy of the interpolation method are evaluated using a cross-validation approach and the estimated errors. The correlation analysis is performed to assess the degree of agreement between observations and the gridded outputs, represented by the grid points surrounding the stations. Furthermore, the representativeness of the new datasets for the study area is evaluated analyzing the capability of the gridded data in reproducing the seasonal time variability and spatial patterns of the temperature variables over Portugal.