If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Ullensvang: The hottest months are usually July and August, with an average temperature of 10°C, while the coldest months are January and February, with an average of -5°C. The rainiest months in Ullensvang are December, October, January and September, with each month seeing an average of 304 mm of rainfall.