In this study, we classified climate zones over South Korea using high-resolution (1 km × 1 km) observational grid data (2000 ~ 2019) and projected future regional climate changes based on high-resolution climate change scenarios (2081 ~ 2100). We applied the K-means clustering method to observational annual mean temperature and total precipitation data to classify South Korea into the following six regions: mountainous-central-high/low elevation (A1/A2), plain-central/southern (B1/B2), and mountainous-southern-high/low elevation (C1/C2). Currently, mean temperatures are highest/lowest at B2/A1 (12.4°C/8.0°C) and total precipitation is highest/lowest at C1/B1 (3312 mm/1182 mm). During the late 21st century, under a low-emission scenario (SSP1-2.6), annual mean temperatures are projected to increase by 2.3 ~ 2.4°C across the six climate zones; under a high-emission scenario (SSP5-8.5), temperature is expected to increase by 5.9°C (C1) to 6.5°C (A2). Total precipitation is projected to increase most in C1 (209 mm/456 mm) and least in B1 (21 mm/155 mm) under SSP1-2.6/SSP5-8.5. Extreme heat events (TXx) will increase across all regions, especially in central areas (A1, A2, B1) of South Korea. Heavy rainfall events (RX1D) will increase most in southern areas (B2, C1, C2), especially in C1, with increases exceeding 100 mm/day. Finally, extreme climate events are projected to occur more frequently across most regions. The intensities of future extreme climate events are expected to increase not only under high-carbon scenarios, but also under low-carbon scenarios. The results of this study are fundamental data for establishing region-specific climate change adaptation strategies.