A librarian at this 10th century monastery leads a visitor beneath the vaulted ceilings of the archive past the skulls of two former abbots.
He pushes aside medieval ledgers of indulgences and absolutions, pulls out one of 13 bound diaries inscribed from 1671 to 1704 and starts to read about the weather.
"Jan. 11 was so frightfully cold that all of the communion wine froze," says an entry from 1684 by Brother Josef Dietrich, governor and "weatherman" of the once-powerful Einsiedeln Monastery.
"But on Jan. 13 it got even worse and one could say it has never been so cold in human memory,"
Diaries of day-to-day weather details from the age before 19th-century standardized thermometers are proving of great value to scientists who study today's climate.
The accounts dispel any lingering doubts that the Earth is heating up more dramatically than ever before
Most historians and scientists delving deep into archives seek accounts of disasters and extreme weather events.