Spring In Jeju 2025 Weather. May is in the spring in jeju and is typically the 6th warmest. With daily highs reaching 12.8°c (55°f), the month showcases a gradual increase in temperatures as the heavy winter coats start to give way to lighter attire.

With daily highs reaching 12.8°c (55°f), the month showcases a gradual increase in temperatures as the heavy winter coats start to give way to lighter attire. May is in the spring in jeju and is typically the 6th warmest.