Observed and simulated precipitation and potential Evapotranspiration for the hydrological summer (May-October) for Geisenheim in the Rheingau region (Germany, 50^∘ North; 8^∘ East) (left panel). Potential Evapotranspiration rates for the observed time period (1958–2013) were calculated according to Penman-Monteith. Simulations were conducted with the STARII model of the Potsdam Institute of Climate Impact using the medium realization run [18] (adapted from Schultz and Hofmann [12]). In the right panel, observed ETp and precipitation data are shown for two Mediterranean type climate locations, one in Avignon, France, the other at Oakville in the Napa Valley, California. Data show 10-year running mean values. Observed data were from the Deutsche Wetterdienst, Germany, the French INRA CLIMATIK, Agroclim database and the US California data provision system on integrated pest management at the University of California, Davis.