Weather conditions in southern Poland at the turn of the 20th century — Insights from archived observational records

This study examines weather conditions in Małopolska (Lesser Poland, southern Poland) from 1861 to 1919, utilizing historical meteorological materials stored in the Archives of the Institute of Meteorology and Water Management — National Research Institute, Poland. The region developed an extensive meteorological network in the latter half of the nineteenth century, preserving daily and sub-daily measurements of air temperature and precipitation, along with notes on socio-economic events and environmental issues. Despite the loss of many early records, the study focuses on 14 measurement points, including the Kraków–Observatory, which has been in operation since 1792 and served as the reference station. Data were digitized through the HISTKLIM project. Analysis revealed that air temperatures in the late 1800s and early 1900s were lower than present-day values, with varied rainfall patterns. The study highlights the substantial value of these historical records, despite gaps and the absence of metadata. Comparing historical weather conditions to current climate normals (1991–2020), the findings contribute to understanding regional climate variability and underscore the importance of preserving archival meteorological data for future research.