Abstract
An attempt to find the optimal timing fot the 62-day summer school holiday in the Czech Republic with regard to climatic conditions has been undertaken. The following climatic factors were considered: air temperature, daylight and bright sunshine duration, the duration of falling precipitation, the duration of fog and mist, the frequency of thunderstorms, and day with thunderstorms.
Also, higher cyanobacteria presence in bathing waters, which is a phenomenon influenced by the weather, was taken into account. The conclusion is that the summer school holidays in the Czech Republic should begin 16 June and end 16 August.
The contemporacy practice used since the beginning of the 20th century is for summer school holidays to run from the beginning of July til the end of August.