Recurrence of hot days in the Stavropol krai under current climate conditions.

Heat is an unfavorable weather phenomenon, as it poses a serious threat to many sectors of the national economy: agriculture, energy, construction, etc. In addition, heat is a meteorological factor, significantly worsening the well-being of weather-sensitive people, people with cardiovascular and other diseases [1, 6]. Thus, the study of the climatic regime of heat is an important aspect in organizing various spheres of human activity. The information base for the analysis of the spatial and temporal distribution of hot days in the region was the observation data of 16 meteorological stations of the Stavropol Krai for 1971–2024, data from the Handbook of the USSR Climate [10] and the monograph Stavropol Krai: Modern Climatic Conditions [3]. The research was carried out using the methods of physical-statistical and regression analysis. For all meteorological stations of the Stavropol Region, the averaged main characteristics of the hot regime for the first 24 years of the new century are calculated: the annual, seasonal and monthly number of hot days and their total duration in the indicated periods. The extreme values of the specified characteristics are determined. The analysis of the annual course of the main characteristics of heat has been carried out. Based on the results of a comparative analysis of the obtained data with data for different long-term periods of the 20th century, a characteristic is given of the dominant trend in long-term changes in the frequency and duration of heat. It is shown that the distribution of hot days in the Stavropol Krai correlates quite well with its landscape structure [12]. In the semi-desert and dry steppe zones of the Krai, about 80 hot days are recorded annually, in the steppe zone of the territory — 60–70 days, in the forest-steppe — 40–55 days, in the mid-mountain zone — about 10 days. On average, about 30 days with extreme heat are observed per year in semi-desert and dry steppe landscapes, about 20 days in steppe, about 10 days in forest-steppe landscapes, about 5 days in the low-mountain zone, and extremely rarely in the mid-mountain zone. Heat as a dangerous phenomenon is recorded throughout the territory of the Krai, except for the low-mountain and mid-mountain zones. Throughout the territory of the Krai, the following is clearly visible: an increase in the annual and summer number of hot and very hot days; an increase in the frequency of heat of the level of a dangerous phenomenon; an increase in the frequency of long periods of heat.