If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Asmara: The hottest months are usually June and May, with an average temperature of 21°C, while the coldest months are January and December, with an average of 16°C. The rainiest months in Asmara are August, July, September and May, with each month seeing an average of 232 mm of rainfall.