As a part of this thesis, measurements were performed in a small sinkhole, which has a horizontal dimension of 70 m and is 9 m deep. The measurements were performed in the period of the 29th of July to the 22nd of August 2019. The analysis shows, that the temperature in the sinkhole can be lower than in the surrounding area for more than 5°C. A cold-air pool in a sinkhole is pretty stable, so the winds that are weaker than 1 m/s cannot mix the air in the cold-air pool with the air above. Such weak winds cannot prevent the occurrence of temperature differences between the sinkhole and the surrounding area. However, especially in combination with wind gusts, they can disrupt the process of cooling in the sinkhole. The difference between the temperature inside and outside of the sinkhole, increases the most around 6 p.m. The intensive cooling continues into the evening. The measurements show, that after midnight the temperature usually does not decrease for more than 5°C.