*3.2. Periods of Low Precipitation Frequency*

The summer drought in terms of periods of low precipitation frequency began on 29 May with the change from cyclonal to anti-cyclonal circulation, which lasted for very different periods of time reaching 100 days in Warsaw and 101 days in Zielona Góra, i.e., until the first days of September. The longest period, i.e., exceeding 90 days, occurred at stations located in the Central Poland Lowlands (up to Warsaw) and the southern part of the South Baltic Lake District. On the outskirts of the mentioned area and in the Lublin Upland, the length of this period was shorter, of the order of 60–90 days. In the Sandomierz Basin and lower parts of the Sudety Mountains, it was a period of 30–60 days, and, in the Carpathian, the period lasted from several to twenty days. On the South Baltic Coast in its western and central part, this period lasted from 30 to 30 several days, while, in the Podlasie–Byelarus Uplands and Podlasie, the period lasted in between 35–37 days. In the surroundings of the Gulf of Gda ´nsk, the Eastern Baltic Coast, and the Lake Districts, the period of low precipitation frequency did not occur (Figure 2).

**Figure 2.** Duration of sequences of days with low precipitation frequency during summer (June– August) 2019. White color—phenomenon does not occur. Black color areas above 500 m above sea level.
