Climate and Bioclimatic Conditions of Kolguyev Island (Barents Sea)

This paper presents the variability of climatic and bioclimatic conditions on Kolguev Island, located in the Barents Sea. The analysis is based on data from the Kolguev Severny meteorological station for the period 1941–2024 and on field observations conducted during June–July of 2023 and 2025. Trends in air temperature and precipitation, as well as the duration of the frost-free and growing seasons, were calculated. The Universal Thermal Climate Index (UTCI) was used to assess bioclimatic conditions. A persistent increase in air temperature has been observed on Kolguev Island throughout the observation period in all seasons, with a marked intensification during the second decade of the 21st century. The dates of the spring transition of air temperature across 0°C have shifted to earlier dates, while the autumn transition has shifted to later dates, resulting in a lengthening of the growing season and an increase in the sum of positive temperatures. During the second decade of the 21st century, a tendency toward decreasing moisture availability on the island has also been observed. Throughout the year, bioclimatic conditions on Kolguev Island are dominated by cold stress of varying intensity according to the UTCI classification, ranging from extreme to slight cold stress. In summer (July–August), about 4% of days fall into the “no thermal stress” category according to UTCI. In the 21st century (2001–2022), the proportion of such days has increased. Field observations on Kolguev Island in June–July 2023 and 2025 indicate the predominance of strong and moderate cold stress conditions. Conditions corresponding to “no thermal stress” occur mainly during the morning and evening hours.