Since the early 2000s, electricity consumption both in the residential and commercial sectors has developed a unique seasonal pattern in Korea. As winter demand has sharply increased over time and has exceeded the summer level in the early 2000s. This is different from demand patterns in the U.S. and EU countries where the annual peak load is observed in a summer month. Using statistical tests, we evaluate if there was a significant temperature increase in winter for recent years. Due to global warming, not only summers but also winters become slightly warmer than before. This leads us to try to explain the recent surge in demand with price factors. This study provides empirical evidence for the distinctive Korea’s winter peak demand attribute to the low price of electricity that has been regulated by the government intentionally. The results suggest that relatively low tariff on electricity compared to other fuel prices can create an excess demand and lead to electricity shortages as well as energy inefficiency.