Precipitation in the West Pomeranian Voivodeship in Poland (1991–2020) – monthly variability

The article presents the spatio-temporal variability of the pluvial conditions in the West Pomeranian province in Poland as per 21 poviats1. The basic data for the study were monthly precipitation totals and maximum 24-hour period total for each month, obtained from 49 stations of the Institute of Meteorology and Water Management National Research Institute in 1991–2020. It was found that area averaged highest values of precipitation, on average, ranging from 71 to 100 mm, were recorded in July (with the exception of the Kołobrzeg and Sławno poviats), and the lowest, ranging from 29–38 mm, were recorded in April. Precipitation in the warm half-year (April–September), depending on a given poviat, ranged from 317 to 444 mm, which constitutes 52–58% of the annual total. Even higher variability was found with respect to the cold half-year (October–March) characterised by precipitation totals within the range of 234–404 mm. In the analysed multi-year period, statistically significant monthly precipitation totals were found only on several occasions: a positive trend was observed in January in the Kołobrzeg poviat, in July in Koszalin and Szczecinek poviats and in October in Myślibórz and Kołobrzeg poviats. The only instance of a marked decrease in monthly precipitation was identified for June in the Kamień Pomorski poviat. In all poviats of the voivodeship, there were nonsignificant tendency of an increase in precipitation in the cold half-year and reduction of the predominance of precipitation in the warm half-year over cold half-year.