Why does Cape Horn have bad weather?

Answer 1

Several conditions contribute to making Cape Horn an especially dangerous passage for ships to negotiate. The absence of land mass below South America (40° south latitude) allows winds to pass freely from west to east. This is further intensified by the fact that Drake Passage, the waters between South America and Antarctica, is relatively narrow (435 nautical miles). The speed of these westerly winds are thus increased as they are constricted through the narrow channel between the Andes mountains and Antarctic Peninsula. The winds in Drake Passage are somewhat unpredictable and can reach up to 40 to 60 knots, and occasionally into the sixties. These winds can also give rise to large waves, especially south of Cape Horn where the sea is more shallow. West of the Horn, one may encounter even more fierce waves, sometimes reaching heights of 30 meters or more. This narrow breach of land has a similar effect on the water, speeding the Antarctic Circumpolar Current as it passes through unabated.

Combine these factors with cold temperatures, jagged shorelines, and stealthy icebergs, and it is easy to see why Cape Horn and Drake Passage have such a notorious reputation.