We estimate the economic benefit of weather modification (precipitation enhancement and fog dissipation) by assuming its operation for the considered regions. Based on the statistical data, the economic benefit of the virtually operational precipitation enhancement experiments for the Andong and Imha basins, where the natural precipitation is relatively lack in South Korea, is calculated 348 for the water resources, 22,458 for forest fire prevention, and 28,458 million won/year for the drought relief. The benefit of the fog dissipation operation for the Incheon International Airport is estimated 7,365 million won/year for the flight delay due to fog. The calculated ratio of benefit to cost for precipitation enhancement operation for the basins is 14.07, which is comparable to that conducted in other countries.