Trends in seasonal precipitation and temperature in Slovenia during 1951-2007

A quality-controlled and enhanced database of 38 temperature and 52 precipitation stations was developed for Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, covering the period 1951-2007. Mean annual temperatures significantly increased in nearly all of Slovenia (except western areas) at rates between 0.15 and 0.36 A degrees C/decade. Warming was most intense strongest in summer and spring in north-eastern Slovenia (0.3-0.4 A degrees C/decade) and weakest in autumn. Precipitation trends were heterogeneous. Annual precipitation decreased significantly in the north-western part, at 3-6 % per decade. During spring and summer, decrease in rainfall by 3-6 % was detected in western Slovenia. No significant trends were found for the autumn season. In winter, precipitation decreased, by 3-12 % per decade, in particular in north-western Slovenia. As observed also elsewhere in Central Europe, changes in large-scale atmospheric circulation patterns may have contributed to the observed long-term warming and drying in Slovenia. However, the strong warming in summer and spring, that is almost twice the trend observed in neighbouring countries, could be enhanced by drier soils caused by the decrease in winter precipitation in Slovenia.