The first mention occurs on June 23: "Schrecklich durchwässerter Zustand des Gartens." There continue, until October, notations about the weather conditions. For instance, on July 3: "Um 7 Uhr von Jena ausgefahren. Schlimmer Weg durchs Mühlthal." Or, on July 9: "Spazierfahrt mit Meyer wegen dem Regen abgekürzt." Or, regarding his visit to the court: "Durch kalte Witterung aus dem Park geschreckt." On July 29, he noted that it had rained the entire night and was continuing. There are entries along these lines: "Anhaltendes Regenwetter." Attempts to take a walk were interrupted by rain. He also noted good weather. June 29: "Erster schöner Tag." On the same day he also drove "am Neuthor" in order to view the flooding.
It is unclear from these entries how much he knew about the cause, but on June 28 he notes a visit of Johann Wolfgang Döbereiner, followed by "Gespräch über die Sonnenflecken. Sauerstoffgehalt der Atmosphäre" (conversation about sun spots; oxygen content of the atmosphere), which suggests that he was being informed about the atmospheric effects of the eruption.
|Constable, Flatford Mill on the River Stour (detail)|
By September there occur more mentions of good weather, and, finally, on October 7: "Schöner Tag. Im Garten."