01 What thermal sign best separates tundra climate from ice-cap climate?
Answer and explanation
Correct answer: A. Whether the warmest month is above or below 0°C
Explanation: In Köppen’s polar group, ET tundra has a warmest-month mean temperature above 0°C but below 10°C, so a short seasonal thaw may occur. EF ice-cap climate has a warmest-month mean temperature at or below 0°C, meaning persistent ice or snow cover is possible throughout the year. Therefore the warmest-month temperature is the decisive sign. Rainfall, wind direction, and daily humidity do not define this distinction.