FLUCTUATION OF MAXIMUM AND MINIMUM AIR TEMPERATURES IN THE CZECH AND THE SLOVAK REPUBLICS

According to the data averaged for eleven representative non-urban stations in the Czech Republic and fourteen stations in the Slovak Republic in the period 1961-1992, the mean air temperatures, mean daily maxima and mean daily minima exhibited a positive trend in winter (statistically significant) , in spring, in summer and in the year, and a negative trend in autumn. Insignificant were changes in the mean daily temperature range within the limits of -0.16 and 0.15 degrees C/10 yr, while a significant positive trend was exhibited by the typical mountain station at Mt. Lomnicky Stit (2635 m). At stations in Prague, affected by the urban heat island, an intensification of positive trends was reflected. Long-term changes of the above temperature characteristics were documented using Prague-Klementinum as an example a typical urban station and Hurbanovo as a locally anthropogenically unaffected station. Changes in mean maxima (with the exception of winter) and of the daily temperature range are closely connected with the cloud cover, while its correlation coefficients with mean minima are not significant. In the case of Hurbanovo there appears a close connection of changes in daily temperature range to relative humidity (with the exception of winter).