Abstract
The study addresses the issue of sultriness in Katowice. The aim of the article is to examine the longterm variability of sultry weather, to determine the annual and daily distribution of sultriness, and to present a detailed description of the circulation and thermal background of this phenomenon. The analysis was performed on the basis of data for the period 1966–2024 from eight measurement terms per day for the IMGW-PIB station in Katowice-Muchowiec. The Scharlau criterion was used to determine sultry conditions. The most important results of the study are as follows: (1) sultriness occurred in the studied period from May to October; (2) statistically significant positive trends in the number of days and number of cases with sultry weather were found, as well as a clear increase in the number and duration of at least 24-hour sultriness sequences; (3) the occurrence of sultry days is primarily favored by the inflow of tropical air and the persistence of cyclonic synoptic situations; sultriness does not occur with the advection of arctic air over southern Poland.