Thermal and precipitation conditions during the long May weekend in Poland and their circulation condition

The objective of the study was to characterise the thermal and precipitation conditions in Poland during the long May weekend and to determine their circulation conditions. This study was based on mean daily air temperature values and daily precipitation totals for the period of 1–3 May in the years 1966–2023. The data were obtained from the resources of the Institute of Meteorology and Water Management – National Research Institute, and made it possible to calculate the mean air temperature for long May weekends in all stations, as well as the precipitation totals. The study revealed the spatial variability of thermal conditions during the May weekend in Poland. The coolest areas were north- ern regions, and particularly the Baltic coast, because of the cooling effect of the sea. The warmest regions were the southern and southwestern areas of the country. Spatial variability was also observed for the precipitation totals. The lowest totals were primarily recorded in central Poland and in the northern regions. Three groups of May weekends were designated in the years under study. The first group was characterised by lower than average air temperature, but higher precipitation, the second one by lower than average air temperature and lower precipitation, and in the third group air temperature was high- er than the average, and precipitation was lower. Each of the types was characterised by a different baric situation.