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 Copan Ruinas: The hottest months are usually April and May, with an average temperature of 21°C, while the coldest months are January and December, with an average of 18°C. The rainiest months in Copan Ruinas are September, June, August and October, with each month seeing an average of 293 mm of rainfall.