Instrumental observations

Abstract

This section gives a synthesis of climate changes in Poland in recent centuries based on instrumental observations. It starts by presenting a detailed history of early instrumental observations carried out in the area of Poland both in its historical and contemporary boundaries. A history is presented of long-term changes (mainly during the last two centuries) observed in the majority of climatic variables (e.g. air temperature, precipitation, atmospheric pressure). Results show that the instrumental history of observations in Poland is one of the longest in the world and that some of the available sources of data have either not been analysed at all or only partially. The mean annual temperatures for the periods 1779-1998 (Warsaw) and 1792-1995 (Cracow) show upward statistically significant trends reaching 0.55°C and 0.52°C per 100 years, respectively. On the other hand, long-term trends in precipitation and atmospheric pressure in Poland have been insignificant. In the twentieth century statistically significant negative trends were observed in Poland for humidity and cloudiness. © Springer Science + Business Media B.V. 2010.