This study analyzed a variation in warmth index and coldness index in South Korea for the past 40 years (1974~2013) and its spatial distribution (2004~2013). To this end, monthly average temperature data in 62 meteorological observation points and 583 meteorological observation points for prevention against disasters in South Korea were used. According to the observed area, the warmth index in general ranged from 56.84(°C·month) to 144.49(°C·month) or so. And an analysis showed that the coldness index ranged from -43.94(°C·month) to 0(°C·month). And overall average warmth index was 104.22(°C·month) and overall average coldness index was -14.42(°C·month). In almost all observation points, these indices tended to increase, and their increase rate was high in an inland urban area in particular. With regard to the spatial distribution, an analysis showed that it was the lowest in the some mountainous areas of Taebaek mountains lying across Gangwon province and around the peak of Mount Halla. And it was high in southwest coastal area including Mokpo, Jeju Island, some areas in the east coast and south coast, and Yeongnam inland regions including Daegu, and so on. It is thought that the above can be utilized as baseline data for explaining the fact such as the productivity of agricultural products, plant phenology, and a change in plant habitat due to climate change.