Calendars with handwritten notices written by Bishop Tomaž Hren contain a number of descriptions on daily weather conditions, especially for fifteen periods of the twelve days between Christmas and Epiphany. Analysis of temperature and precipitation conditions is based on their conversion into symbols. Particularly in the second and the third decade of the 17th century, Bishop Hren entered in the calendars and in his two manorial minutes from Gornji Grad extensive data on weather conditions during lengthier periods of time. According to the analysis, the resulting weather anomalies generally, although not entirely, match the weather data recorded in other parts of Central Europe. Hren’s entries made it possible to discern certain climatic characteristics of some parts of the Slovene territory in the early 17th century.