The Valley's Topoclimate and Its Influence on The Vegetation Abstract The thesis as presented deals with specific valley's topoclimate of a chosen example of one particular valley located near the city Jílové u Prahy. The main objective of the thesis which has been defined is to evaluate the topoclimate of the determined area and its influence on the phytogeographical and phenological situation of the valley. The outdoor temperature measurements carried out by using Assmann's psychrometer as well as the observations of the plant's phenological state have been taken in the course of repeated expeditions into the valley in 2011 and 2012. The formations of night valley's inversions have been confirmed. The temperature gradient of 6 řC and three and half an hour long inversion following the sunrise have been recorded as a result of the measurement performed on 28th April 2012. As a consequence of the valley's parts shading the temperature differences have been proven. As a referential meteorological station the faculty's own station situated on the peak of Pecný hill and the automated personal weather station in Okrouhlo were used. The lower temperatures in the valley have a clear impact on the commencement of the plant's phenological stages. A detailed phenological scale was created in order to observe...