The paper presents a function-type relation which demonstrates that volumetric moisture of the surface horizon of soil has an effect on the intensity of atmospheric water infiltration during non-rainfall periods. The relation, developed and then verified on the basis of independent material, reveals that the intensity of infiltration decreases with an increase in volumetric moisture of soil. For the case presented herein, infiltration ceases when volumetric moisture is higher than 0.15 m3 m−3. The developed function also takes into account the effect of atmospheric conditions through the introduction of another argument into the domain. The aforementioned is in the form of potential condensation efficiency measured on a dew collector, and assumes the form of a modified logistic function.