Дослідження сезонних тенденцій зміни приземної температури повітря в Україні (1990—2021)

This study examines the spatial and temporal characteristics of surface air temperature (SAT) changes in Ukraine from 1990 to 2021. It focuses on the seasonal and regional variabilities, long-term trends, the harmonic characteristics of the annual temperature cycle, and their implications for regional climate change. From meteorological observations at 93 weather stations (Ω93 dataset), the average annual SAT was 9.6±0.8 °C. Over the past three decades, the mean rate of temperature increase reached a significant +0.64± 0.01 °C per decade, substantially exceeding historical averages. This warming trend is further evidenced by annual temperature anomalies, which showed only three years (1993, 1996, and 1997) with negative anomalies (ranging from −0.32 to −0.55 °C), while the remaining years were anomalously warm, with peaks in 2007, 2015, 2019, and 2020 (reaching up to +2.79 °C). Monthly SAT trends revealed statistically significant warming across nearly all months, ranging from +0.34°C to +1.19 °C per decade. The most intensive warming was observed in December (+1.19±0.14 °C per decade), particularly in northern and eastern Ukraine. Conversely, January exhibited minimal or even negative trends in many regions, except for Crimea and southern Ukraine, where moderate warming persisted. The amplitude and phase of seasonal SAT variations are reliable indicators of continental climate characteristics. In 1990—2021, the mean amplitude of the seasonal temperature cycle was 12.3 ± 1.0 °C, with a decreasing trend of approximately 0.1 °C per decade. This decline is largely attributed to warming during the warm season. The mean phase of the seasonal cycle was estimated at 1.29 ± 0.06 months. A slight phase shift of −0.012 months per decade was also observed over the study period. The study highlights increased temperature variability during winter and spring months, contributing to a more comprehensive understanding of contemporary climate shifts in Ukraine. These findings underscore the urgent need for adaptive strategies to mitigate the impacts of ongoing climate change.