Final answer:
Type C climates are temperate with milder winters, thanks to their proximity to oceans, whereas Type D climates are continental with more extreme seasonal changes and colder winters.
Step-by-step explanation:
The distinction between the Köppen climate types C and D is primarily based on the temperature and geographical location of the regions they cover. The type C climates, known as temperate or moderate climates, generally have milder winters, without extreme cold, and thus are classified apart from the colder type D climates using an isotherm of -3°C. Type C climates typically exist nearer to oceans which buffer temperature extremes.
Type D climates, known as cold or continental climates, are characterized by a more significant range in temperatures, with hot summers and cold winters. These are usually found interior of continents or at higher latitudes than type C climates. Seasonal changes are more pronounced in type D climates, with the possibility of severe winter conditions including snow, which contrasts with the more constant temperatures experienced in type C climates. One of the examples of a region with type D climate is North Dakota, in contrast to Japan which predominantly experiences a type C climate.