In 2025, the National Library of the Czech Republic proudly joins the Czech Hydrometeorological Institute (CHMI) in commemorating 250 years of continuous temperature measurement at Clementinum. This extraordinary scientific tradition—ongoing since 1775—is not only a milestone in Czech meteorology but a cultural and historical treasure preserved within the very walls of the National Library.

A special exhibition on the Library’s Students’ Courtyard invites the public to explore the fascinating development of meteorology in the Czech lands and around the world. Visitors will meet the pioneers of early weather observations, follow the evolution of meteorological instruments, and discover the stories of observation networks and major climate events. Special focus is given to Clementinum’s uninterrupted temperature series, one of the oldest of its kind globally.

The exhibition also presents current meteorological technologies and the work of CHMI today. Through the collaboration of CHMI and the National Library, the display is enriched by panels created by our experts, providing historical context and showcasing the unique setting of Clementinum—home to both science and knowledge.

To accompany the exhibition, a popular science book “Measured at Clementinum…” has been published, and an engaging cipher game will lead participants through Prague’s historic centre while uncovering meteorological milestones. In June, a series of public lectures will be held in the Library’s lecture hall, offering deeper insight into this exceptional legacy.

As the guardian of the Clementinum complex, the National Library is honoured to share in celebrating this unique blend of science, history, and culture—right at the place where Czech meteorology began.