In this Master of Science Thesis we investigate a number of meteorological variables and their influence on the daily incidences of cardiovascular diseases (CVDs) in Denmark along with their lagged effect, since earlier studies have shown that the occurrence of incident CVDs varies according to time of year with the highest daily rates of incident CVDs during winter. The thesis is divided into three parts. The first part contains materials and methods, including a description of CVDs and data sources along with validation of diagnoses and an analysis strategy. The second part contains results of the analyses conducted by using generalized additive models (GAMs) and dynamic linear models (DLMs). The third part of the thesis consists of the mathematical theory used for the analyses. Results using GAMs show that temperature has a significant influence on CVDs, but the results are not unequivocally saying that temperature has the highest impact on the daily incidences of CVDs in the winter. Results using DLMs give a more consistent result which indicates that high temperatures have a negative effect on the daily counts of incident CVDs in Denmark.