If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Trpanj: The hottest months are usually August and July, with an average temperature of 24°C, while the coldest months are January and February, with an average of 10°C. The rainiest months in Trpanj are November, December, October and January, with each month seeing an average of 185 mm of rainfall.