The aim of this research is to determine the range of air temperature and precipitation fluctuations in Warsaw and Krakow, in the last two Centuries. This research is to show the synchronization of cyclic climate fluctuations in Poland on the example of the above cities, and also to forecast the temperature and precipitation variations in the 21st Century. Past analyses of long-term surveys (Warsaw 1779-1998, and Krakow 1826-1998) suggest several air temperature cycles of significant amplitudes. They are ca. 3-5, 7-8, 10-13 and 73-113 years long, and the planetary cycle lasts for 178.9 years. Spectres and cycles of air temperatures, precipitations, NAO indicator, and sun activity were calculated based on the �regression sine� method. Interesting are the graphs of temporal changes in sun activity, and the North Atlantic Oscillation (NAO) indicator with forecast until 2100. Reconstructions and forecasts were arrived at based on interferences of the detected cycles: Wolf numbers and NAO indicator. Temporal air temperature courses in Europe in the last centuries evidence that contemporary climate warming in a large degree may have resulted form natural causes. Not without any meaning are almost congruent regression straights of standardized values of sun activity and air temperature in Warsaw between 1779-2000.