temperatures in the Karasjok series

Due to the HistKlim project the sub daily data series from Karasjok was digitised and quality controlled. The present report discusses some problems with missing values in the period 1879-1889 where many interpolations had to be done in order to fill the gaps. The uncertainties of the interpolations were assessed for daily as well as for monthly values. In the database, however, only interpolated monthly values were accepted. The standard error of the interpolations of the monthly mean temperatures varies with the month of the year. The errors are much larger in winter than in summer, about 1 oC during winter and 0.2 oC or less during the season April – September (AMJJAS). If the data coverage in a month is 50 % the uncertainties are reduces by 71 % compared with a situation were all values in the month are missing