Campus Rena Transportation Accommodation About Rena Possibilities in the area Campus Rena - the Place for the future! Typical of the inland areas of southeast Norway, it has a continental climate with warm and dry summers and cold, snowy winters. Whereas days don’t end in June, there are only a few hours of sunshine in December. Weather forecast for Rena. Published: Wednesday 21 April 2010. Last change: Monday 07 March 2016.