The mercury hit an all-time high of 40.4 degrees Celsius (104.7 degrees Fahrenheit) in the Czech village of Dobrichovice, south-west of the capital Prague, the CHMI state meteorological service said Monday.
Temperatures soared to a searing 40 degrees Celsius in several other towns across the country, according to the Czech CTK news agency.
Monday's national high tops the previous record of 40.2 degrees Celsius set on July 27, 1983, in the Prague-Uhrineves suburb.
Hot air masses from Morocco and Spain are responsible for the ongoing heatwave searing the Czech Republic, meteorologists said, also predicting it would last several days.
Local authorities have issued heat stroke warnings for the elderly and the ill.