*3.4. Climate Water Balance (CWB) for June, July, August with Aspects of Regional Variation*

In June 2019, the greatest water deficit occurred in the central Poland belt, especially its central and western parts with a maximum in Pozna ´n at 176.6 mm. The water deficit decreased towards the north, south, and east. The lowest values of water deficit occurred in Eastern Baltic Coast and Lake Districts with the minimum of −71.3 mm in K ˛etrzyn. Lower deficit values were recorded in southern Poland with a minimum of −34.1 mm near Lesko. The mean value of CWB in Poland was −129 mm (Figure 4a). In June 1981–2010, the highest water deficit occurred in central Poland, especially in its central and western part with its maximum in Pozna ´n at 106.7 mm. Water deficit decreased towards the north and south. The smallest deficit values occurred in the Eastern Baltic Coast and the Lake Districts with the minimum of −69.5 mm in Koszalin. Much lower values of deficit were recorded in southern Poland with a minimum of −12.9 mm near Lesko. The mean value of CWB in Poland amounted to −79 mm (Figure 4b).

**Figure 4.** Climatic water balance (CWB) in June: (**a**) 2019; (**b**) 1981–2010. Explanation same as in Figure 2.

In July 2019, the largest water deficits occurred in the western part of the South Baltic Coast with a maximum of <sup>−</sup>109.8 mm in Swinouj´ ´ scie. Slightly lower values were observed in central Poland ranging from −60 mm to −90 mm. The lowest values of water deficit were observed in the eastern part of South Baltic Coast, Eastern Baltic Coast and Lake Districts and locally in the south of Poland. In the vicinity of Katowice, an excess of 6.1 mm was recorded. The average CWB over Poland was −64 mm (Figure 5a). In July 1981–2010, the highest water deficits occurred in western part of the South Baltic Coast with a maximum of −69.9 mm recorded in Ustka. Slightly lower values were observed in central Poland ranging from −30 to −60 mm. The lowest values of water deficit occurred in the southern part of Poland. In the vicinity of Bielsko–Biała and Lesko, an excess of water was recorded, at 19.1 and 13.5 mm, respectively. The mean CWB value over Poland was −36 mm (Figure 5b).

In August 2019, the largest water deficit values were characterized by the South Baltic Lakes region, especially around Słubice, Gorzów Wlk., and Pozna ´n from −92.4 mm to −100.6 mm. As one moved away from these regions, a decrease in water deficit values in all directions was observed. Smaller values of water deficit were recorded in the north-eastern part of Poland and in the south of the country from −1.5 mm to −19 mm. Locally, in Kielce, Bielsko–Biała, and Lesko, there was an excess of water, with recordings of 23.8 mm, 18 mm, and 1.4 mm, respectively. The mean CWB value over Poland was −53 mm (Figure 6a). In August 1981–2010, the highest values of water deficit were characterized by the eastern part of Poland, especially near Terespol and Włodawa, which saw values of −55.8 mm and

−55.7 mm, respectively. Smaller values of water deficit occurred in northern part of Poland and in the south of the country, ranging from −1.5 mm to −30 mm. The mean value of CWB in Poland was −38 mm (Figure 6b).

**Figure 5.** Climatic water balance (CWB) in July: (**a**) 2019; (**b**) 1981–2010. Explanation same as in Figure 2.

**Figure 6.** Climatic water balance (CWB) in August: (**a**) 2019; (**b**) 1981–2010. Explanation same as in Figure 2.

In light of the comparison presented, June saw with the highest temperature deviation from normal and low rainfall, and was the month with the highest CWB deviation of 50 mm. The values of these deviations from normal decreased to −28 mm in July and −15 mm in August (Table 1).


**Table 1.** Comparison of mean climatic water balance (CWB) values (mm) over Poland in the months June–August in 2019 with values from the 1981–2010 multi-year period.
