If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Kostitsi: The hottest months are usually August and July with an average temp of 71°F, while the coldest months are January and February with an average of 40°F. The rainiest months in Kostitsi are November, December, January, and February, with each month seeing an average of 9 inches of rainfall.