ИСТИНА

The urban ‘dry island’ (UDI) phenomenon over Moscow city has been studied and analyzed for the last 124 years by the data of the ground meteorological network. It concludes into less values of relative humidity in a city in the comparison with surrounding rural zone. Mean-annual water vapor pressure E doesn’t demonstrate systematic changes in Moscow during the last 146 years. Unlike it mean-annual relative humidity demonstrates quick and systematic (steady in time) fall with the average rate of K = –0.06 [%/year]; in other words, it decreased from 81 % in 1870s to nearly 72 % in recent years. Inside the city it is the result of general T increase due to both global warming and, besides, intensification of Moscow UHI. Long-term changes of the F spatial field in Moscow city have been studied in details for separate periods since 1890s till recent years. The absolute value of the urban ‘dry island’ intensity is increasing in time: from –4 % at the end of the 19th century to –8 % now. Unlike average dryness, average humidity does not demonstrate stable in time local effects such as urban island.