Abstract
In the article, daily rainfall values were used to analyse water conditions in Western Polesie. The SPI standardized precipitation index was calculated based on weighted averages from 1986–2015 for various periods. Based on time sequences for periods of 1, 3, 6, and 12 months, periods with different moisture levels were distinguished. It has been shown that the average frequency of dry and wet periods is 27.2 and 31.4%, respectively. Four intense drought periods were identified: 1990–1993, 2002–2006, 2007–2008, and 2019–2020. Drought was most often associated with deficient monthly and annual rainfall, 20 and 450 mm, respectively. Three wet periods were identified in 1997–1999, 2009–2011, 2013-14. Excess water was associated with high monthly rainfall above 150 mm. In the 21st century, there has been a statistically significant increase in the frequency of dry and wet periods and of longer duration.