The data set includes irregular sea level heights observations made from 1782 to 1794 by the physician Leonardo Vordoni in Trieste, Italy, but in those times under the Austrian rule. The time series starts on 1 January 1782 and ends on 12 October 1794. The observations were performed twice a day until June 1791 and more frequently afterwards. The original heights are expressed in Paris feet and inches (1 ft = 32.4845 cm), relative to the green belt formed by algae on a pole. The data were digitized from original handwritten documents and quality-checked as far as possible.