Goethe's other scientific interests were concerned almost exclusively with three topics: anatomy, geology and meteorology, and all of them engaged his attention from the period of his first stay at Weimar onwards. His diary of 1780 shows that he was collecting specimens of stones and rocks at that time; in 1782 he wrote an account of the mineralogy of Thuringia; and in 1784 he kept a geological notebook of his visit to the Harz mountains. In the same year he wrote the essay Über den Granit, and his account of his Italian journey (1786-8) frequently refers to the various rock-formations he encountered. There appears to have been something of a lull between 1788 and 1804, when botany and optics held his chief attention (although some of the numerous undatable geological essays may belong to this period), but from then until his death the flow of geological writings is almost unbroken.

The history of his meteorological studies is similar. A letter to Frau von Stein of 1779 appears to mark Goethe's first observation of cloud-formation while another of 1784 reveals his interest in ‘Toaldo's weather-cycle’, and his desire for a barometer and thermometer with which to keep records. His diary for September 1786 also shows an attempt at explaining the formation of clouds in general terms, and later in the same year, while at Rome, he asked Frau von Stein for weather-data from Weimar.