There's nothing like an all-inclusive holiday in Gwangyang to rejuvenate you, especially when you know what to expect from the elements. Here's some information to help you choose when to book: The hottest months are usually August and July, with an average temperature of 23°C, while the coldest months are January and February, with an average of 4°C. January and December are the driest months, while July and August are the rainiest months.