Abstract
Analysis of time series was performed of cloudiness, air temperature and precipitation for the years 1951–2000, the data used representing lowland Poland. The properties of the temporal course of these elements of climate and the interrelations between their variability in time have been determined. The strength of dependence of precipitation and temperature upon the magnitude of cloudiness in the annual cycle has been assessed with the linear correlation coefficient. The essential climate-forming role of cloudiness has been confirmed. The magnitude of cloudiness over Poland explains up to 70% of variability of temperature and precipitation. These interrelations are the strongest in the warmer half of the year. Atmospheric circulation and cloudiness explain up to 85% of variability of the climate elements studied.