Which continent has no Köppen arid (B) climate?

Antarctica is the continent with no Köppen arid (B) climate. Although it is widely described as a polar desert because it receives very little precipitation, its climates are classified as polar, mainly ice-cap (EF) and locally tundra (ET), rather than arid.

Köppen’s B group is defined by precipitation that is low relative to evaporation, but the system treats sufficiently cold regions separately. Polar climates have no month with an average temperature above 10°C, and ice-cap climates have monthly averages below 0°C throughout the year. Most of Antarctica meets the EF definition.

This creates a memorable terminology trap: “desert” is a general climate description based on dryness, whereas “B” is a specific Köppen group. Antarctica can therefore be a desert in the geographic sense without being a B climate in the classification system.

Antarctica is also the driest continent overall, with much of its interior receiving only a small amount of snowfall each year. The snow that does fall usually remains because temperatures are too low for regular melting, gradually building the continent’s vast ice sheet.