Classification of the atmospheric droughtiness index fields in view of the modern climate change problem

In this paper, a classification of the droughtiness index fields and excessive moistening Si in the European part of Russia in May–June and July–August 1940–2000 is given. It is shown that, in May–June, the occurrence frequency of drought conditions significantly increased from the first to the second half of this period, while in July–August, the drought occurrence frequency remained almost the same.