Observations collected between 2000 and 2008 at the Cabauw meteorological measurement platform in the Netherlands were conditionally sampled to select nights with stably stratified atmospheric conditions, clear skies and weak horizontal wind speeds (<3ms−1). For these conditions the eddy-correlation latent heat fluxes are found to be negligibly small, while the conditionally sampled surface energy balance exhibits a maximum residual. However, inspection of the specific humidities for these conditions reveals systematic drying trends that are a maximum at the lowest measurement level above the surface. These drying trends occur for any prevailing wind direction. Latent heat fluxes are calculated from the humidity budget equation and from a Penman-Monteith dewfall model, with the results suggesting that during clear, stable nights the observed latent heat fluxes as obtained from the eddy-correlation technique are erroneously small.