The main objective of the paper concerns the determination of the annual and multi-annual variability of air flow over East-Central Europe in the period 1871–2010. Daily mean sea-level pressure and values of physical quantities provided the basis for distinguishing 27 circulation types, i.e., eight directional cyclonic, transitional, and anticyclonic types, and one non-directional cyclonic, anticyclonic, and an undefined type. Over the area of East-Central Europe, the highest frequency is recorded for air flow from the western sector, with a maximum in the period from December to January. In spring, a higher than average frequency of cyclonic and easterly circulation is observed, and in summer—anticyclonic and northerly. Increased zonal circulation was recorded in the years 1910–1930, and particularly after 1970, and eastern at the end of the nineteenth century and in the 1930s and 1940s. An increase in the frequency of days with non-directional anticyclonic type and westerly air flow, and a simultaneous decrease in frequency of days with south-easterly and easterly circulation were observed throughout the study period. Among the three classes of circulation types, the highest persistence (particularly in winter) was recorded for anticyclonic types, i.e., when the high pressure system occurred over the Scandinavian Peninsula or East Europe.

This study aims to characterize temporal and spatial trends of sunshine duration in Poland based on data from the years 1971–2018 and to make an attempt to explain their causes. Daily sunshine duration came from 31 Polish meteorological stations. Data from 10 stations came only from a traditional Campbell–Stokes heliograph, while in the other 21 synoptic stations Campbell–Stokes heliograph was replaced with an automatic sensor in 2014 and since then only such data are available. The smallest sunshine duration occurs in December (average areal total—39.7 hr), and the highest in July (average areal total—230.1 hr). The spatial distribution of sunshine duration in Poland shows great diversity associated with different day lengths depending on latitude. In the cool part of the year (November, December, January, and February) the isolines of totals of sunshine duration run from the highest values in the south to the lowest in the north of the country, while in the months of the warm part of the year (March to September) the system is reversed. The multi‐annual trends in sunshine duration in Poland are similar to the changes taking place in other parts of the world. The years 1971–1980 mark the end of “global dimming,” which was manifested in very low values of actual and relative sunshine duration. “Global brightening” confirms a statistically significant growing trend in sunshine duration at all the analysed meteorological stations in Poland from April to September. There is a strong statistically significant relationship between the areal totals of sunshine duration and the type of pressure system, average monthly cloud cover, and atmospheric optical depth.

This study evaluates the relationship between atmospheric circulation conditions and the frequency of heat/cold stress in Lublin in the years 1951-2010 according to the Universal Thermal Climate Index (UTCI). The paper outlines the frequency and conditional probability of heat/cold stress during particular circulation types and analyses the circulation patterns that induce these incidences. Increased wind velocity had a significant effect on creating unfavourable bioclimatic conditions in winter. Meanwhile, in summer, heat stress was observed almost exclusively when a high pressure system from eastern Europe induced a slow inflow of very warm air masses from the east or south.