Soil radon potentials have been calculated for developing radon potential maps of twelve counties in North-Central Florida, including Alachua, Citrus, Clay, Duval, Flagler, Lake, Levy, Marion, Nassau, Putnam, St. Johns, and Volusia Counties. The maps are designed to show from soil and geological features the areas that have different levels of radon potential. The soil radon potential maps have been proposed as a basis for implementing radon-protective building construction standards in areas of high radon risk and avoiding unnecessary regulations in areas of low radon risk. The soil radon potentials calculated in the report are revised from previous radon potentials to utilize improved map polygon definitions and variability estimates.