THE EFFECT OF VARIATIONS IN AMBIENT AIR TEMPERATURE AND HEATING SEASON LENGTH ON THE NUMBER OF DEGREE-DAYS ON THE EXAMPLE OF THE CITY OF CZESTOCHOWA

An analysis of variations in ambient air temperature, the length of the heating season and the number of degree-days in the area of the City of Czestochowa has been made in the paper. The analysis of the collected data has shown that, for the coldest eight heating seasons, the occurrence of minimum daily temperatures at a level lower than t(e) = -20 degrees C concerns only five of them, and the average five-day ambient temperatures for those heating periods have indicated that the calculation temperature for Climatic Zone III (t(e) = -20 degrees C) was not exceeded in any case. On the basis of the obtained results it has been found that, the value interval of the relative number of degree-days falls between 0.9 and 1.1. The performed analyses have shown an increase in the value of seasonal ambient temperature and a decrease in the relative number of degree-days with successive heating seasons.