Actual evapotranspiration (ETa) is hard to measure accurately over large areas. We studied ETa data from lysimeters at different sites in Germany to see if measurements from small areas can represent larger regions. We found that daily ETa measurements from lysimeters show high spatial correlations for distances up to 50km, similar to measurements from eddy covariance systems. The amount of water available in the soil (ET0) is the main factor influencing these correlations.