If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Giresun: The hottest months are usually August and July, with an average temperature of 21°C, while the coldest months are January and February, with an average of 7°C. The rainiest months in Giresun are October, June, May and September, with each month seeing an average of 193 mm of rainfall.