The paper presents a model of seasonal water pricing (SWP) aimed primarily at diminishing excessive fresh water use in the city of Belgrade. Seasonal prices are determined on meteorological observations of the average monthly temperatures and the total monthly precipitations in the period from 2000 to 2010, and their deviations from the thirty year normal levels. The SWP operation is based on an ex-post price determination, and it conveys a signal to water users on resource scarcity. Not knowing ex ante how high their monthly bill is going to be, but aware of the price-setting rule, consumers will be in a situation to change their pattern of behaviour towards a more sustainable water use. Potential of the SWP model implementation are a) pushing consumers towards rationality, b) valuable resource conservation and c) enabling the water supply company to cover peak-season supply and the related costs. The SWP model has been created for the Belgrade Water and Wastewater Company, but might be easily implemented in all other cities with the same problems.