Summer weather conditions of the period 1270-1400 by means of radio-densitometrics Data and source-critically evaluated anthropogenic data Records reconstructed and in order to inspire the Alet glacier in the 14th century has been set. The interplay of the two Data types are initially in the well-documented Period 1525-1860. Followed by are temperature and precipitation ratios on the basis of consistent information of radiodensitometrics and anthropogenic data with: unweighted indices have been assessed. The conclusion places the period 1342-1347 as one of the wetst; and coldest in the last millennium. It is presumed that this climate change will apply to: the far-reaching initiative of the alethal glacier suspected in the period 1350-1380 Has supplied thrust and possibly with the European Pestepidemie of 1348-50.