Climatology of the relative humidity in the Carpathian Valley

The reports about the climate change mostly focus about the trend of the temperature or precipitation. However, the relative humidity is also an important characteristic of the atmosphere, e.g. it impacts both the cloud and fog formation. The trends of the relative humidity in the changing climate have been found to be rather uncertain.  In this research the climatological trend of the relative humidity in the Carpathian Valley was studied. Analysis of the long-term observed database from eight meteorological stations was used to present the annual and seasonal trends of the relative humidity. The annual trend was found to be between 2-3% in every meteorological station. The results show that the relative humidity has decreased every season but in autumn, when the trend of it has not been consistent. While the most significant decrease has been occurred during spring, the decrease was negligible during autumn.