Abstract

We studied long-term changes in temperature extremes in Georgia against the backdrop of ongoing global warming within 1961–2020. Using observational data from 20 meteorological stations from different physical-geographic regions of the country, we analyzed the main climate temperature indices recommended by the WMO and the Expert Team on Climate Change Detection and Indices (ETCCDI). Indices characterizing extremely cold and warm conditions (ice days, frost days, summer days, and tropical nights); growing season length; as well as indices of absolute extremes and percentile temperature characteristics were considered. The results show that along the Black Sea coast and the Kolkheti Lowland, changes in temperature indices are less pronounced due to the moderating influence of the sea and humid landscapes; however, a significant increase in the number of tropical nights is observed. In areas with a more continental climate (Eastern Georgia, the South Georgian Highlands, and the mid-mountain zone of the Greater Caucasus), a general decrease in the number of ice days and frost days was observed, along with a simultaneous increase in the number of hot summer days, tropical nights, and growing season length. Tropical nights and percentile temperature indices were found to be the most sensitive to global warming. Overall, the results indicate widespread long-term tendencies consistent with regional manifestations of global warming, characterized by decreases in cold extremes and an expansion of warm indices. However, the statistical robustness and explanatory power of these trends vary substantially across physical-geographical regions and specific indices. Many significant shifts exhibit low coefficients of determination (R2 < 0.1), indicating that although long-term warming trajectories are real, local topography and intense interannual natural variability remain the primary drivers of annual temperature fluctuations in Georgia.

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