I am calculating Heating Degree Days and Cooling Degree Days for European Nordic countries (Norway, Sweden, Finland, Denmark, Estonia, Latvia and Lithuania). On a paper (Benestad 2008) I read that the base temperature is bounded between 18°C and 22°C, but this value is too much generic for my purposes, as I have to compute exact HDD and CDD for the aforementioned countries. Where can I retrieve Base Temperature values for Nordic countries?
UPDATE: I found that EUROSTAT use a value of 15°C as base temperature for computing HDD and CDD. Would it be acceptable?