If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Tarkwa: The hottest months are usually January and February with an average temp of 81°F, while the coldest months are August and July with an average of 76°F. The rainiest months in Tarkwa are June, May, October, and September, with each month seeing an average of 13 inches of rainfall.