The study analyzes hourly NmF2 data from Juliusruh (1957 to 2023) and examines the response of NmF2 to solar flux by using three different solar EUV proxies for six solar cycles, including a separation of the ascending and descending phases. The response is better represented with a quadratic regression and F30 shows the highest correlation for describing NmF2 dependence over time. These results revealed a steady decrease in NmF2, influenced by the intensity of the solar activity index.