*2.3. Meteorological Conditions*

Meteorological data for the years 2000–2019 were obtained from the meteorological stations at the Variety Assessment Experimental Plants belonging to the Central Research Center for Cultivated Plants (Dukla, Nowy Lubliniec, Przecław and Skołoszów), in the region of Southeastern Poland and from the Agrometeorological Bulletins of the Institute of Meteorology and Water Management [21]. The CLIMGEN model [22] was used to analyze the data.

The station in Dukla (49◦33 N, 21◦41 E) is located in the southwestern part of the Podkarpackie Province at an altitude of 324 m above sea level, with an average annual temperature of 7.3 ◦C and annual rainfall of 887 mm. Unlike other stations, it was characterized by high rainfall throughout the growing season. The highest amount of rainfall was recorded there in 2001 (830 mm) and the lowest in 2008 (476 mm) (Table 1).

The warmest year was 2008, with an average air temperature of 15.0 ◦C, while the coldest one was 2005 with an average air temperature of 13.2 ◦C. All the years were wet, and the hydrothermal coefficient oscillated between 3.1 and 1.7. Optimal hydrological and meteorological conditions occurred only in 2007 [24,25] (K = 1.3).


*Climate* **2022**, *10*, 57

The station in Nowy Lubliniec (50◦17 N 23◦05 E) is located at an altitude of 217 m above sea level and is characterized by an average annual air temperature of 7.3 ◦C and a total rainfall of 665 mm (Table 1). The average long-term air temperature in Nowy Lubliniec ranged from 13.8 ◦C in 2005 to 15.5 ◦C—in 2003. The highest amount of rainfall occurred in July 2003 and amounted to 239 mm, while the lowest value of this feature was recorded in 2006—11 mm (Table 2). The sum of atmospheric precipitation in the analyzed years ranged from 563 mm in 2000 to 352 mm in 2006. The hydrothermal index ranged from 1.2 to 2.2, with the optimal years being 2007–2008, while they were wet for the remaining years [24,25] (Table 1).


**Table 2.** Statistical characteristics dependent and independent variables.

Y—yield; X1—temperature of the April–May; X2—temperature of June–July; X3—temperature of August–September; X4—rainfalls of April–September; X5—indicators of hydrothermal of April–September.

The meteorological station in Przecław, located in the northern part of the region (53◦22 N; 14◦28 E), at an altitude of 185 m above sea level, was characterized by different meteorological conditions and characterized by an average temperature of 8.1 ◦C and annual rainfall in the amount of 644 mm. The warmest year in this region was 2008, with an average temperature of 8.7 ◦C. In 2004, the temperature and precipitation conditions during the potato growing season were optimal (K = 1.2). Most of the years analyzed were wet, with the index ranging from 1.3 to 1.9. The highest amount of rainfall in the April-May period was recorded in 2001 (523 mm), and the lowest in 2004 [24,25] (326 mm) (Table 1).

According to the weather station in Skołoszów (49◦55 N 22◦48 E), located at an altitude of 204 m above sea level, the average annual air temperature was 8.3 ◦C, and the annual rainfall was 667 mm. The warmest year was 2018, and the average air temperature in the period from April to September was 17.0 ◦C, while the coldest was 2005, with an average temperature of the growing season of 14.0 ◦C. The lowest amount of precipitation during the vegetation period was recorded in 2004 (297 mm), and the highest was recorded in 2002 (591 mm). The least favorable distribution of precipitation took place in 2008. The years 2000, 2003 and 2008 can be described as quite dry, 2005–2007 can be descripted as optimal, 2008 can be described as quite humid and 2002 is described as wet [24,25] (Table 1).
