The great amounts of precipitation are to be found in the mountains of the Ukraine, where rising currents of air help along the condensation of the water vapor. Even in the Low Beskid the precipitation exceeds 1000 mm. (Yasliska 1170 mm.), in the Gorgani and Chornohora we find in large areas, especially on the southern slope, a precipitation of over 1200 mm., in a few places 1400 mm. (Kobiletzka Polana 1377 mm., Bradula 1419 mm.). The amount of precipitation is still large in the entire Pidhirye, but at only a short distance it decreases considerably. Lemberg has only 735 mm. of rainfall, the southern part of the Rostoche as much as 900 mm. in places, since the western edges act like chains of mountains to the west winds. But Czernowitz, near as it is, has only 619 mm. and the Podolia on the Dniester still less. The Khotin lying in the yar of this river has only 300 mm., which best illustrates the significance of local conditions. At a greater distance from the curve of the Carpathians the amount of precipitation shows a slow but regular decrease toward the southeast. Only in the northern part of the Rostoche and the northwestern part of Podolia does the amount of precipitation attain 600 mm., while further toward the south and east a wide zone stretches out with only 500 — 600 mm. (Pinsk 581 mm., Kiev 534 mm., Uman 546 mm., Poltava 532 mm.). Another wide zone, which extends from the mouth of the Dniester to the bend of the Don, has a precipitation of between 400 and 500 mm. (Kharkiv 465 mm., Katerinoslav 475 mm., Kishinev 471 mm., Yelisavet 444 mm., Odessa 408 mm.). The next narrow zone of the Pontian and Crimean steppe has a precipitation of less than 400 mm. (Mikolaiv 360 mm., Sevastopol 386 mm., Luhan 379 mm.), a corner of Crimea on the peninsula of Tarkhankut has even barely more than 200 mm.
The Yaila Mountain Range is too small to have any marked influence on the increase in the amount of precipitation. Yalta has only 508 mm. precipitation. On the other hand, the influence of the Caucasus is very great. The sub-Caucasus Kuban region, to be sure, has only 400 — 500 mm. precipitation, Stavropol 7 20 mm., N ovorossy sk 691 mm. However, the amount of precipitation on the southwestern side of the Caucasus Mountains increases uncommonly. At the borders of Ukrainian territory, Sochi has not less than 2071 mm.
From this account we see clearly enough that, in comparison with Central and Western Europe, the Ukraine is rather poor in rainfall, especially in the southeast. But the distribution of the precipitations among the seasons is so favorable that most of them fall at the time they are most needed, namely, in the early part of summer. The entire Ukraine lies within the area of the summer rains, only the narrow strip of the south coast of Crimea and the Caucasus are within the area of the winter rains.
The reason of the preponderance of the summer rains lies in the western and northwestern Atlantic winds, which, in that season, have easy access far into the southeastern part of the Ukraine. These winds bring so much moisture into the Ukraine that almost two-thirds of the annual rainfall belongs to May, June and July. The month with the greatest amount of precipitation for the entire Ukraine is June. Only the Polissye, Northwestern Volhynia and the western part of the Kiev territory show the heaviest precipitation in July, since, in these regions of forests and swamps, evaporation is heaviest at this time of greatest heat.
The summer rains of the Ukraine differ from those of Central or Western Europe in their heaviness. Only in the Western Ukraine are the summer rains of the type of gentle rains that are uniform for an entire country; in the south and east they appear as cloudbursts in heavy showers. In Samashcani, in Bessarabia, there have been times when 200 mm. of rain fell in a single day, in Korovintzi in the Poltava region, 5 mm. in one minute. In the Pontian steppes all rain falls in the form of heavy showers. The water flows off quickly and evaporates rapidly, before it is able to thoroughly saturate the ground..
Electric discharges and hailstorms occur in close connection with the summer rains, most frequently in June, less so in July and in May. They usually come from the southwest in the afternoon hours. Most of these storms originate in the Carpathian Mountains and reach Volhynia and Kiev, but do not cross the Dnieper. The Caucasus, too, has very many storms. Hailstorms are most frequent in Galicia and Volhynia and the western part of the Kiev regions; very rare in the southeast.