Three relationships between surface heat flux, boundary layer height, and lapse rate from the literature are evaluated using data taken in summertime continental conditions. Simple relationships work well for diagnosing boundary layer height if the heat flux and lapse rate are known. Under these conditions (moderate heat flux, moderate to deep boundary layers) accounting for other effects such as shear and spin-up is not necessary. It is not possible to determine whether subsidence is significant due to the uncertainties of the measurements.