The process of climate warming significantly affects agroclimatic resources and agricultural production. We study the agroclimatic resources and their variability on the territory of the Republic of Bashkortostan (Russia). The Bashkortostan has a high agricultural potential and holds a leading position in the country in the production of grain crops, potatoes, milk, and honey. Currently, no detailed studies have been conducted for this area to assess the effects of global climate change on agro-climatic resources. World experience shows such research becomes strategically important for regions with powerful agricultural production. We used the sums of average daily air temperatures above 0 and 10 °C, the G.T. Selyaninov hydrothermal coefficient, and the Ped aridity (humidification) index as agroclimatic indicators. We used data of long-term meteorological observations of 30 meteorological stations for the period of 1961–2020. We revealed the long-term dynamics of the agroclimatic indicators and the spatial and temporal regularities in their distribution on the territory of Bashkortostan. There is a steady increase in the sums of average daily air temperatures above 0 and 10 °C. Against this background, aridity increases, which is especially manifested in the southern parts of the Republic of Bashkortostan. We assessed the impact of agroclimatic indicators on the main types of agricultural crops in the republic. We revealed that the greatest positive impact on the yield of oilseeds, cereals, and industrial crops is made by precipitation at the beginning (r = 0.50, r = 0.44, and r = 0.52, respectively) and in the middle of the growing season (r = 0.55, r = 0.76, and r = 0.51, respectively). Temperature and precipitation during the growing season have a complex effect on cereals. This is proven by correlations with HCS and the Ped index (r = 0.45 and r = −0.56, respectively). Aridity at the beginning of the growing season affects the yield of oilseeds and potatoes. This is confirmed by correlations with the Ped index (r = −0.49 and r = −0.52, respectively). In general, the aridity of the growing season has a significant impact on the yield of cereals (r = −0.57). Negative relationships have been found between the air temperature growing season and the yield of potatoes (r = −0.50) and cereals (r = −0.53). The results of the study were compared with data from the Copernicus Climate Change Service database. We identified climate trends under RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5 scenarios. These scenarios should be taken into account when developing plans for the adaptation of agriculture in the Republic of Bashkortostan to changes in the regional climate. Maximum decrease in precipitation is established for the RCP 6.0 scenario. This can have an extremely negative impact on crop yields. This problem is especially relevant for the southern part of the Republic of Bashkortostan. The information presented in the study will allow for a more effective adaptation of the agricultural sector to current and future climate changes.

The results of the study of changes in the thermal regime in the cold period on the territory of the Republic of Bashkortostan are presented. The relevance of this study is due to the fact that the observed climatic changes may have different intensity within the Bashkir Pre-Urals, the Southern Urals and the Bashkir Trans-Urals. The assessment of regional changes in the thermal regime of the cold period was carried out on the basis of methods of statistical analysis of data from long-term observations, traditionally used in studies of this kind. The statistical significance of the values was estimated at a 95% confidence level. The data of observations at 30 meteorological stations of the republic in the period 1961-2020 were used for the analysis. It was found that the average monthly air temperatures tend to increase, statistically significant temperature increases are characterized by January (0.64°C/10 years), February (0.57°C/10 years) and March (0.47°C/10 years). The air temperature increases more significantly in the Pre-Urals (0.16-0.70°C/10 years), the smallest increase is observed in the Trans-Urals (0.13-0.40°C/10 years). In the considered 60-year period, more than half of the cases of temperature anomalies relate to the criteria of “warm season” (24 cases – 40.0%) and “very warm season” (7 cases – 11.7%). A reduction in the duration of the cold period in the republic was revealed due to the shift of its start date to a later date (1.8 days/10 years), and the end – to an earlier date (-1.0 days/10 years). During the correlation analysis, it was found out that the increase in air temperatures in the cold period is associated with a decrease in the blocking processes of the Scandinavian oscillation and an increase in zonal circulation created by the Arctic and North Atlantic oscillations.