Extreme summer and winter temperatures in the Czech Lands after A.D. 1500 and their Central European context =Teplotně extrémní zimy a léta v českých zemích od roku 1500 a jejich středoevropský kontext

Abstract

Extremely cold/mild winters (DJF) and extremely cold/warm summers (JJA) in the Czech Lands were derived from se- ries of temperature indices based on documentary evidence (1500-1854) and from series of air temperatures measured at the Prague-Klementinum station (1771-2007) over the past 500 years. Altogether 24 cold winters, 23 mild winters, 18 cold summers and 21 warm sum- mers emerged. Czech extremes were compared with the Central European temperature series and series of documentary-based temperature indices for the Low Countries, Germany and Switzerland. Analysis of composite sea level pressure fields confirms advection of cold air from the north-west (extremely cold summers) or from the east (extremely cold winters). Mild win- ters are related to warm airflow from the west or south-west and extremely warm summers to the influence of high pressure related to the Azores High. Spatial correlations of extremes for winters proved better than for summers. We demonstrate that documentary evidence ex- plains temperature variability for winter better than it does for the other seasons