During a lake/sea breeze,an airflow trajectory reversal generally occurs at the leading edge (lake/sea breeze front) of the landward advancing marine air and can significantly affect the use of an off-site dose assessment procedure. Knowledge of the location of the lake/sea breeze front in real time is vital in interpreting the results from a conventional straight-line Gaussian off-site dose calculation methodology, which ignores this complex flow pattern. A simple, low-cost technique was developed to estimate the location of the lake/sea breeze front in real time from easily obtainable meteorological parameters recorded at National Weather Service stations. Although this technique was developed for lake breezes occurring near the Wisconsin Public Service Kewaunee nuclear plant, the concept is applicable after site-specific modifications for other lakeshore sites in approximating the location of the lake breeze front.