The heating degree-day is a quantity used in relating air temperature to heating fuel usage. Value of the coastal heating degree-days are rather small compared to the corresponding values from the interior of Croatia. That fact as well as the other characteristics of the coastal degree-days enable a proper way to thrifty plan a period and a place for the indoor activities (e.g. congress tourism) over heating season there, and to save a lot of energy at last. This paper discusses the methods od degree-day analysis which give the most convenient results for that kind of planning and compares results for several coastal locations with the corresponding results for one location in the interior. Compared are degree-day calculations based on several values for base temperatures, which are taken also for KUENzgrada project dealing with the determination of some state heating temperature criteria.