In the thesis we focused on the processing of climatic characteristics, which were measured at the climatological station Oravská Lesná located in the northern part of Slovakia. We processed the data during the summer half-year from April to September for the observed period of 2014 - 2018. We tried to capture the climate development in the area, compare these climatic characteristics while comparing them with the long-term average. The measured characteristics, such as average air temperature, rainfall sum, sunlight and number of days with defined air temperature, were processed into tables and graphs. All data was taken from SHMÚ. We have assessed the impact of climate change on the forest and forest ecosystem. In the theoretical part we described the development of meteorology and climatology, the observation network of climatology, the basic methods of measuring individual climatic variables and we briefly described the activities of SHMÚ. This work provides a wealth of information on climate change at the Oravská Lesná station in 2014 - 2018 and at the same time describes the effect of climate change on the forest.