The aim of this paper is to analyze the production and runoff of cold air in flood control reservoirs around Graz, Styria. This topic is a physical geographic one and is part of local climatology. There are four measurement station in these flood control reservoirs and they are home-made built. But they are just measuring the air temperature. The aim of these measurement stations is to analyze cold periods during the winter 2015-2016. All of these investigation areas have similar topographic conditions, but not exactly the same ones. These investigation areas should be investigated based on small differences. All measured data will be evaluated and interpreted. Also different reasons for the production and the runoff of cold air will be analyzed too. All different illustration facilities will also be explained, discussed and interpreted. Reference data will also be used to validate results. The measurement station Graz-West provide these reference datasets. All in all the comparison between measured datasets and reference data is very important and interesting. The focus of all elevations lies on temperature minimums.