Documentary evidence of extreme weather and climate events in Poland in the 16th century

Extreme weather and climate events (WCEs), including severe frosts, cold and warm waves, and anomalous seasonal conditions, represent critical components of climate variability with profound societal impacts. While recent studies have reconstructed medieval extremes in Poland, the sixteenth century remains a particularly important yet underexplored period, marking the early phase of the Little Ice Age and characterized by increasing climatic instability across Europe.

This study reconstructs temperature-related extreme events in Poland during the 16th century using a comprehensive body of documentary evidence, including chronicles, municipal records, ecclesiastical sources, and early weather diaries. Following established historical climatology methodologies, all records were critically evaluated and systematically classified into five categories: severe frost, cold waves, river/lake/sea ice events, snow and snowstorms, and heat and warm waves. Each event was assigned temporal, spatial, and intensity attributes, along with a reliability assessment.

Preliminary results indicate a continued high frequency of winter-related extremes, particularly severe frosts and prolonged cold waves, often associated with extensive river and Baltic Sea ice formation. Compared to the late medieval period, the 16th century exhibits a persistence of cold extremes alongside a notable occurrence of summer heat and drought episodes. This dual signal suggests enhanced seasonal contrasts and increased interannual variability rather than uniform cooling. Temporal clustering of high-impact events is evident, with several decades characterized by repeated extreme conditions.

Spatial analysis reveals concentrations of recorded events along the Baltic coast and major river basins, reflecting both climatic exposure and the distribution of archival sources. Documentary evidence also highlights significant socio-economic impacts, including crop failures, transport disruption, and food shortages, indicating heightened societal vulnerability to compound climate hazards.

The reconstructed series is broadly consistent with other European studies documenting increased climate variability during the early Little Ice Age. By extending the analysis into the 16th century, this study provides a crucial bridge between medieval reconstructions and early instrumental observations, offering new insights into the evolution of extreme climate events and their impacts in Central Europe.

This research contributes to a better understanding of long-term climate variability and emphasizes the value of documentary evidence for assessing historical climate risks in the context of ongoing global change.

 

This work was supported by the National Science Centre, Poland, project No. 2020/37/B/ST10/00710.