Biometeorological conditions at Polish Antarctic Station (King George Island, West Antarctica) according to Universal Thermal Climate Index, 2013-2023.

The Universal Thermal Climate Index (UTCI) was used to estimate thermal stress for humans in the South Shetland Islands (West Antarctica), the region in Antarctica with the highest number of scientific stations and visiting tourists. This was done to analyze the duration of comfortable weather conditions, which are crucial for conducting fieldwork and other outdoor tasks. The UTCI is one of the most commonly used climate thermal indices, but it had not previously been calculated for any region in Antarctica. The research was based on hourly data (air temperature, humidity, global solar radiation and wind speed) derived from the Henryk Arctowski Polish Antarctic Station between 2013 and 2023. The range of hourly UTCI values indicates conditions ranging from no thermal stress to extreme cold stress, with predominant strong cold stress (–26.9 to − 13.0 °C; 40.5% of cases) and very strong cold stress (–39.9 to − 27.0 °C; 25.3% of cases). In such conditions, it is recommended that physical activity is increased and that the extremities and face are protected from the cold while working outside, as well as increasing the thermo-isolation properties of clothing. The same thermal stress class remains for more than one day sporadically. The most favourable conditions for spending time outside (without thermal stress or with slight cold stress), which lasted 7–9 consecutive hours, occurred rarely and only from December to March. Due to high wind speed, some UTCI values fall outside the thermal stress scale; nevertheless, the authors classified these as extreme cold stress and suggest developing the UTCI formula to make it more applicable in regions where very high wind speed occur.