Fragmentary Weather Records from Cádiz (Spain) in the 18th Century: Insights from Archival and Library Sources

This study focuses on the recovery and digitization of three fragmentary meteorological datasets from the archives of the Royal Observatory of the Spanish Navy in Cádiz, covering selected days in 1776, 1788, and 1793. These records include temperature, pressure, and occasional wind observations originally linked to astronomical measurements. After manual transcription and quality control, the historical data were compared with long-term climate statistics from the period 1955–2021 for Cádiz. Despite the absence of metadata on instruments and installation, the 18th-century observations show reasonable agreement with present-day seasonal patterns, indicating their reliability. Wind data, although limited, were documented using an eight-point wind rose and terminology consistent with historical standards. These findings highlight the scientific and historical value of scattered early observations. They provide reference points for validating historical reanalysis and suggest that additional records may exist in naval archives. Continued efforts to recover such data will improve long-term climate reconstructions for southern Spain and beyond.